MPSA Psi 2011

PSI ΨThe McGill Undergraduate Psychology Journal

Issue 1April 2011

Editors-in-chiefLisa Zhang

Stephanie Wong

Editorial BoardHeather CameronJessica Gallinger

Nicole GileadiAllison Goodwin-Wilson

Molly JacobsKarissa Leduc

Alexandra PriorJordana Shell

Jessica Thompson

Layouts and DesignsDavid Chak

Letter from the Editors

This issue represents a series of firsts. As the editors-in-chief we received Psi’s first ever submissions, put together its first editorial board, and created the first of what hopefully will be many issues of Psi: The McGill Undergraduate Psychology Journal.

With firsts in mind, we chose for the cover one of the first ever drawings of a neuron, done by Santiago Ramón y Cajal in 1899. Though we are not making great leaps in the understanding of neuroanatomy with this humble journal, we have inherited some of the spirit of discovery behind that drawing. Psi is the first journal at McGill that specifically seeks to publish the work of psychology undergraduates. We hope that this journal will help give McGill undergraduate psychology students a forum in which they may share their discoveries as they inquire and explore within the still young field of Psychology.

Lisa Zhang

Stephanie Wong

Contents

Functional Differences between Magnocellular and Parvocellular Pathways in PrimatesNora Mulloy - 1

Autonomy: A Potential Protective Factor Against Ego-Depletion?Natalie Zacchia - 5

Role of COMT in the Me-diation of SchizophreniaSonia Hussain - 13

Cooking Up Creativity: A Critical Analysis of The Talent Code: Greatness Isn’t Born. It’s Grown. Here’s How. By Daniel Coyle Leora Frimer - 23

Autonomy: A Potential Protective Factor Against Ego-Depletion?David Atia - 27

Empirical Evidence for a Relationship Between Exercise and Decreases in Depression and AnxietyZoë Prowse - 39

The Role of Mass Media Influences on Women’s Body Image and Their Mental/Behavioural StatesBryan Lin - 45

Stress and the Common Cold: A Review PaperRauvynne Sangara - 51

Functional Differences Between Magnocellular and

Parvocellular Pathways in Primates

Nora Mulloy

AbstractAn understanding of the foundations of primate vision is necessary for a comprehensive approach to larger questions in vision science. This paper explores the fundamental research into the magnocellular and parvocellular pathways, and a review of their subcortical roots is provided. A number of distinct functional differences exist between the two pathways: colour, speed, acuity, and contrast sensitivity. The possibility that the distinctions continue into higher processing areas in the visual cortex is examined. Evidence from neurophysiology, anatomy, and psychophysics is included.

IntroductionHuman vision is an extraordinary feat that allows for interaction with the environment at all levels. From the hunter stalking his prey attuned to movement, distance, and depth to the painter composing a scene of fine detail and color, the visual system conveys a vast amount of information in a seemingly fluid and flawless manner. In an attempt to understand how this task is accomplished, vision scientists break down the process into its simplest constituent parts using methods from neurophysiology, anatomy, and psychophysics. Much of this basic information is carried along two parallel paths: the magnocellular or M pathway, and the parvocellular or P pathway. This discussion examines the roots of the pathways, presents evidence of lower-level subcortical physical and functional differences between them, and explores the possibility that these distinctions

continue into higher-level processing in the visual cortex.

Roots of the Pathway Sensory input from the rods and cones collect behind the eye in the retinal ganglion. The cells of the retinal ganglion fall into two main categories. Magnocellular cells have large branched dendritic fields, larger axons, and large receptive fields. Parvocellular cells are about eight times as numerous, with small dendritic fields, small axons, and smaller receptive fields (Merigan, 1991). P cells receive input from cones that are spatially separated across the retina. Their responses are more sustained than the transient responses of M cells, which receive input from cones that are not spatially distinguished (Schiller, 1990). In their review of the

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Psi ΨIssue 1 April 2011

M and P pathways, Livingstone and Hubel (1995) point to an experiment in which subjects followed alternations in brightness more quickly than alternations of color. Since the M pathway has been shown to be color-blind (Merigan 1991), this evidence substantiates the speed of response distinction.

Based on anatomical research, particularly staining studies, it is known that M and P cells remain quite segregated upon departure from the retina, suggest-ing a separation of function (Merigan, 1991). From the retina, the M and P pathways enter the dorsal area of the region of the thalamus known as the lateral geniculate nucleus, or LGN. Receptive field properties here are generally the same as those in the retinal ganglion (Bruce, Green & Georgeson, 2003). The M and P inputs seem to be well organized in the LGN’s six layers. The M pathway occupies layers 1 and 2, and the P pathway occupies layers 3 through 6, with each pathway containing equal inputs from the contralateral and ipsilateral eyes. This physical separation allows lesioning studies to be a reliable and successful method of studying functional distinctions between the two pathways (Snowden, Thompson & Troscianko, 2006). It is also important to note that the LGN retains retinotopic mapping throughout its six layers, allowing experimenters to predictably present a stimulus inside and outside an area of visual space of a mapped LGN lesion.

Subcortical Functional DistinctionsOn the subcortical level of processing, there are several main distinctions in M and P function: colour, speed, acuity, and contrast sensitivity. Merigan studied the first distinction, colour, by performing acrylamide lesions of P cells in the retinal ganglion. These lesions reduced subjects’ colour sensitivity by a factor of thirty. Moving upward, physical lesions of P layers in the LGN made it impossible to measure threshold for color sensitiv-ity, while lesions of the M layers had no effect (Mer-igan 1991). Subjects were presented with a set of stimuli and were rewarded for saccadic eye

movements to the target stimulus, or the stimulus whose color did not match the rest. All stimuli were isoluminant, to ensure that color vision was necessary to successfully complete the task. Physical lesions to P layers decreased performance on this task by about 70 percent, while subjects with M layer lesions did not show any deficit (Schiller, 1990). Taken together, these results confirm the hypothesis that the P pathway is responsible for color vision, while the M pathway is colorblind.

The second main distinction, speed, refers to the abil-ity of each pathway to perceive temporal change such as movement and flicker which correspond to a more general property of temporal resolution. Schiller presented his lesioned subjects with a flicker detection task, based on the same principle as the previously mentioned color task. A variety of preset flicker rates were used for both red/green and monocromatic LED trials.

M-lesioned subjects showed a decreased level of cor-rect responses, while P-lesioned subjects showed no deficit (Schiller, 1990). Merigan’s study showed simi-lar but more nuanced results. He found that M lesions decreased movement detection only at lower temporal frequencies, using an opposite direction discrimination task (Merigan, 1991). These results suggest that the M pathway shows greater motion sensitivity than the P pathway at higher temporal frequencies, or when a stimulus is not tuned to the somewhat higher level of contrast preferred by P cells, which will be discussed in the next section.

The next distinction, acuity, refers the visual system’s ability to discern fine detail or fine shape. This ability is often measured in terms of spatial frequency, and is tested using sinusoidal grating patterns (Figure 1). Merigan found that his retinal ganglion P pathway acrylamide lesioned subjects showed reduced spatial resolution. Similarly, subjects with LGN P lesions showed a four-fold decrease in performance on acuity tasks. M lesioned subjects showed no such deficit, suggesting that the P pathway is responsible for fine perception skills (Merigan, 1991). Schiller’s results support this idea. He also performed


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stimulus discrimination tests using high contrast checkerboard patterns, with the target stimulus hav-ving a differing spatial frequency in order to evaluate perceptual ability for texture and pattern. Subjects with lesions in the P layers of the LGN showed significantly poorer performance (Schiller, 1990). P cells are thus tuned to higher spatial frequencies and M cells to lower spatial frequencies. Merigan suggests that these results should not come as a surprise, as P cells are far greater in number and density, and so should be expected to offer greater acuity (Merigan, 1991).

The final distinction, contrast sensitivity, refers to the visual system’s ability to detect differences in luminance, which is again tested using sinusoidal grating patterns (Figure 1). Merigan measured contrast sensitivity in control and acrylamide P lesioned subjects. Lesions produced decreased contrast sensitivity, especially at high spatial frequencies and lower temporal frequencies, or the area of the spatio-temporal field occupied by the P pathway. Sensitivity was unaffected under the opposite conditions. Testing of subjects with physical LGN lesions produced the same results (Merigan, 1991). Schiller likewise found that lesion-ing of the P pathway decreased contrast sensitivity (Schiller, 1990). These results serve to underscore the necessity of ensuring that test stimuli fall within the perceptible range for a pathway, so that the pathway has the best opportunity to perceive it to give unbiased data.

Figure 1 left - grating with low contrast and high spatial frequency; right - grating with high contrast and low spatial fre-quency

Higher Level FunctionalDistinctionsOutputs from the LGN are carried to the visual cortex, most clearly to area V1, where M and P cells officially terminate in layer 4C (Bruce, Green & Georgeson, 2003). Projections of M are thought to extend to 4B, area V2, and area V5, which includes the MT region believed responsible for knowledge of where and how (Livingstone & Hubel, 1995). This conclusion makes sense given that M cells are favoured in motion perception.

The P pathway is thought to extend through V1 into V2 and V4, where lesions impair color and pattern perception (Bruce, Green & Georgeson, 2003). However, these conclusions are not without controversy, and are not nearly as clear cut as subcor-tical distinctions.

The colorblindness of the M pathway likely carries through cortically, at least to some extent. Living-stone has found that cortical cells with M input lack an equiluminance response (Livingstone & Hubel, 1995). However, as Schiller points out, colour percep-tion deficit observed with LGN lesions is more pro-nounced than in V4 (Schiller, 1990). Ferrera’s lesion studies of P or M LGN layers measured subsequent output in area V4. Both lesions reduced V4 activity to some degree, suggesting that V4 receives both M and P input, and so neither dominates the color/form pathway function ascribed to V4 (Ferrera, 1992). P pathway lesioned subjects performed poorly on Shiller’s shape discrimination task, though only on difficult to distinguish shapes (Schiller, 1990). This finding correlates with Ferrera’s. The M pathway likely plays some role in the V4 colour/form pathway, but perhaps only with coarser forms

As mentioned, input to the MT or motion area of the cortex is populated by much more M input than P input. Ferrera’s data on V5 and MT response before and during M and P lesions confirms this, as response dipped significantly only with M blockage (Ferrera, 1992). Additionally, Livingstone points out that the


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colorblindness, fast speed, low acuity, and high contrast sensitivity (Livingstone & Hubel, 1995).

A more complex perceptual skill processed in the cortex is stereopsis or depth perception, which also aids in movement. Neurons in V2 and area MT have been found to be selective for specific binocular disparities. .Livingstone maintains that the M pathway input correlates with this MT processing. This view is held in part because depth is best detected when the stimuli have M-type traits – high temporal fre quency and low contrast. An important depth cue, shading, depends on luminance contrast rather than color vision, as does motion parallax (detection of depth from motion) (Livingstone & Hubel, 1995).

Livingstone presents the idea that the M pathway into the cortex is specialized for a “global function” that allows for understanding of a scene, while the P pathway and its cortical projections are used for finer elements of perception like color and detail (Liv-ingstone & Hubel, 1995). Others maintain that this view is an oversimplification. For example, Schiller found that P lesioning causes a deficit in stereopsis at higher spatial frequencies. He believes that these higher centers receive dual M and P input (Schiller, 1990). Ferrera agrees, arguing that there is no simple correspondence between LGN inputs and cortical responses, but that the interactions are asymmetric

(Ferrera, 1992).

ConclusionAs is now clear, the parvocellular and magnocellular pathways possess certain distinctions in anatomy and function in subcortical visual processing. Small numerous P cells preferentially process fine detail and lower temporal frequencies and serve as color processors. Larger and sparser M cells collect information on high frequency motion and low con-trast images, producing transient color-blind re-sponses. Physical segregation of the two in the LGN has made it possible to confirm these properties and explore others. Segregation of M and P

function at higher cortical levels is possible, but remains difficult to clearly determine, and most data suggest some mingling between the two. Continuing to study vision’s simplest and most basic functions will likely lead to greater knowledge of the M and P pathways and their processes at ever higher levels.

ReferencesBruce, V., Green, P.R., & Georgeson, M.A. (2003). Visual Percep tion. 4th ed. Hove, England: Psychology Press.Ferrera, V.P. et al. (1992). Mixed parvocellular and magnocellular geniculate signals in visual area V4. Nature, 358, 756 - 758.Livingstone, M.S., & Hubel, D.H. (1995). Through the eyes of monkeys and men. In Gregory et al.’s (Ed.), The Artful Eye. Oxford, England: Oxford University Press.Merigan, W. (1991) M & P pathway specialization in the Macaqu -e. In A. Valberg and B.B. Lee (Eds.), From Pigments to Perception. Nato ASI Series, Vol 23. New York: Plenum Press.Schiller, P.H. et al. (1990) Functions of the color-opponent and broadband channels of the visual system. Nature, 343, 68-70.Snowden, R., Thompson, P., & Troscianko, T. (2006). Basic Vi sion. Oxford, England: Oxford University Press


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Autonomy: A Potential Protective Factor Against Ego-Depletion?

Natalie Zacchia

AbstractCurrently, about one in every four Canadians is following or would like to follow a diet. Dieting requires persistence; one must be able to stick with a diet regimen. It also requires performance and self-control; one must eat well (make the proper choices) and resist temptation. One factor that helps to determine dieting success is type of motivation. Autonomous motivation is consistent with one’s values, beliefs and goals while controlled motivation pressures individuals to behave in ways that are consistent with the values, beliefs and goals of other people or of society. The present study examined ego depletion (loss of self-control resources) and the role of motivation in the domain of healthy eating. Participants were either left with a unappetizing or appetizing food for five minutes. Appetizing food was meant to deplete the ego since self-control would be required to resist eating the food. Participants were then given a task that required self-restraint and their performance and persistence on this task were measured as signs of ego depletion. We found that those with autonomous motivation were better able to perform and persist at the task compared to those with controlled motivation

IntroductionCurrently, about one in every four Canadians is following or would like to follow a diet (Babcock, 2004). In order to follow a diet, one must avoid giving into temptation and instead eat healthier food. Dieting requires persistence; one must be able to stick with a diet regimen. It also requires performance and self-control; one must eat well (make the proper choices) and resist temptation. Dieting goals are difficult to achieve and many people do not succeed in these goals. Others, however, can and do succeed in maintaining healthy diets. What sets these two types of people apart may be due to many factors, and one of these factors may be motivation.

Autonomous versus Controlled MotivationThere are two main types of motivation: autonomous and controlled (Baumeister, 2002). Autonomous motivation comes from within and is consistent with one’s values, beliefs and goals. Controlled motivation comes from outside and controls or pressures individuals to behave in ways that are consistent with the values, beliefs and goals of other people or of society; this motivation compels people to act in ways that are not necessarily consistent with their independently held values. Autonomous motivation results in greater persistence and better performance on tasks that require self-control while controlled motivation

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results in less persistence and lower performance (Moller, Deci, & Ryan, 2006). Additionally, Moller, Deci, & Ryan (2006) have proposed that “ego depletion” moderates the relationship between the type of motivation and levels of persistence and per-formance.

Ego DepletionAccording to the self-regulatory strength model proposed by Roy Baumeister (2002), ego depletion is the temporary state wherein one’s will-power or self-control, both limited resources, are depleted. Exerting self-control or making effortful choices may deplete one’s future self-control or willpower. Self-control is defined as the ability to control one’s impulses so as to act in accordance with the values and expectations of oneself or of society (Baumeister, Vohs & Tice, 2007). It has been shown that people tend to break their diets more often at night than at other times of day. This finding is interesting because people also tend to be more ego depleted at night (Baumeister, 2002). This research suggests that there may be a real-life linkage between ego depletion and dieting.

Previous ResearchUsing self-control to resist eating tempting foods has been studied in the past. One study asked participants to choose between radishes and cookies, and then perform an unsolvable task. Those who resisted the temptation of eating the cookies were more ego-depleted than those who chose the cookies, as evidenced by their levels of persistence in the subsequent task. (Baumeister, Bratslavsky, Muraven, & Tice, 1998).

Another study showed dieters to be more ego depleted than non-dieters when shown appetizing food. In this case, ego depletion was measured by the amount of ice cream they later consumed (Vohs, & Heatherton, 2000). These studies show that resisting appetizing food can cause ego depletion since participants who saw appetizing food had less self-control left over to persist on later tasks. Previous research has also investigated whether the type of motivation one has can affect persistence and

performance on tasks (Moller, Deci, & Ryan, 2006). People who feel more external control (controlled motivation) perform worse and persist for less time on a task relative to people who feel more autonomous. Ego depletion is explained as the reason for this difference in persistence and performance. Ego depletion was measured by performance and persistence on an e-hunting task (where participants were instructed to find and cross out all e’s in a text, unless doing so violated certain rules) (Moller, Deci, & Ryan, 2006).

Present ResearchThe present study examined ego depletion and the role of motivation in the domain of healthy eating. The difference in ego depletion between people with autonomous motivation and people with controlled motivation was investigated. Participants’ type of motivation for the goal of eating healthy was measured before coming into the lab. When they arrived, they were randomly assigned to a condition, and were either presented with a bowl of unappetiz-ing food or a platter of appetizing food. Participants were then given a task that required self-restraint (e-hunting task). Their performance and persistence on this task were measured as signs of ego depletion. Participants then completed a self-report assessment of ego depletion and were given suspicion and manipulation checks. Finally, subjects were debriefed and invited to ask any questions they might still have concerning the study.

We hypothesized that participants with autonomous motivation would a) perform better on the task, b) persist for longer on the task, and c) report less ego depletion than those with controlled motivation. Another hypothesis was that autonomy would serve as a protective factor against ego depletion. That is, participants who had autonomous motivation and were in the appetizing food condition should be able to perform better, persist for longer and report less ego depletion than those with controlled motivation in the same condition.


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MethodParticipantsFifty-five participants were recruited to complete the study, all of whom were McGill undergraduate students (N=55). Most of these students participated in order to receive an extra credit in class. This was accomplished through the McGill Subject Pool website that offers students the opportunity to either participate in a study or to read an article and write a report for extra credit in a course. Other study participants included friends and people recruited through an email sent out to all McGill undergraduate psychology students. Participants were randomly assigned to one of the two conditions.

Design and ProcedureDesign. The overall design was a between subjects quasi-experiment. The participants’ randomly assigned condition (unappetizing or appetizing food) was our independent variable. The appetizing food condition was designed to be ego depleting because participants would be tempted to eat the food and would have to exert self-control not to eat it (n=28). In this condition, participants saw a platter of appetizing food while they signed their consent form and waited for the experimenter (five minutes). The platter contained chips (Cheetos, Lays, Miss Vickies and Doritos), chocolate bars (Caramilk, Kit Kat, Aero and Coffeecrisp), candy (Swedish Berries and Cherry Blasters), and cookies (Chips Ahoy chewy chocolate chip cookies). This platter of food had a post-it note on it which said: “Dr. Baldwin’s Party Platter” in order to throw off any suspicion. The non-appetizing food condition was designed not to be ego deplet-ing since participants should not have to exert self-control to abstain from eating the food (n=27). In this condition, participants saw a bowl of radishes while completing their consent form and waiting for the experimenter (five minutes).

A questionnaire which assessed participants’ reasons for wanting to eat healthy was the second independent measure. This questionnaire was the Treatment Self-Regulation Questionnaire (TSRQ) –

diet version, and has been used and validated by the Self-Determination Theory Lab at the University of Rochester (Ryan & Deci, 2008).

The dependent measures used to test the hypotheses included performance and persistence on a task, and a self-report of ego-depletion. Other dependent measures, not directly related to the main hypotheses included temptation, hunger and amount of time since participants last ate. These dependent measures were used as control variables to see if they had any effects on the main relationship we investigated. Procedure and materials. Participants were instructed to fill out a questionnaire online before coming into the lab in order to assess their type of motivation. Those who came into the lab who had not already filled this out online were instructed to fill it out at the end of the experiment. The TSRQ-diet assesses whether people’s reasons for wanting to eat healthy are controlled, autonomous or if they have amotivation (i.e. no motivation). The possible responses to this questionnaire followed a Likert scale and ranged from “not at all” (1) to “somewhat true” (4) to “very true” (7). Of the fifteen questions, six measured autonomous reasons, six measured con-trolled reasons, and three measured amotivation. Re-sponses to these categories were used as scores on the three subscales: autonomous motivation, controlled motivation and amotivation. An example of a ques-tion measuring autonomy on the TRSQ is as follows: “The reason I would eat a healthy diet is because I personally believe it is the best thing for my health.” The responses of the autonomous items were aver-aged along with the responses of the controlled and amotivation items. items were averaged along with the responses of the controlled and amotivation items. The amotivation subscale’s purpose was to identify and then exclude any participants who had high amotivation (were not motivated at all). Since none of the participants scored highly on the amotivation subscale, no one was excluded. Subtracting the average controlled score from the average autonomous score provided the “Relative Autonomous Motivation Index”. A median split was performed to get a group that was high in


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autonomy (n= 28) and a group lower in autonomy (n=27).

Participants came in at staggered intervals and were first brought to a storage room. They were instructed to read and fill out the consent form while the experimenter got the study set up and they were told that the experimenter would return to get them. In this room, there was a tea kettle, coffeepot, cups, coffee filters, stir sticks, and the food to which they had been assigned. All items were placed near the food so that the food would not look out of place or suspicious. A timer was set for five minutes once the experimenter left the room. The purpose of leaving participants in the room for five minutes was to make the manipulation more salient.

Participants were then brought to a second room and were seated at a desk with a computer. Dividers were placed on either side of the desk to prevent distractions. The participants were given the e-hunting task which involved crossing out all the e’s from a text unless doing so violated certain rules (see Baumeister et al., 1998). The participants received three pages from an introduction to statistics textbook which was printed on a light setting and minimized, making it harder to see (from Ferguson & Takane, 2005). A fifteen minute time limit was set so that if participants had not already stopped by then, they would be stopped by the experimenter. The instructions were posted on the computer screen.

While completing this task, participants were instructed to press down on the spacebar. They were told that they could stop anytime they liked but they should find as many qualifying e’s as they could before stopping (see Baumeister et al., 1998). As stated on the screen, when they were ready to stop they had to lift their finger off of the spacebar (passive response) and press the letter q on the keyboard (in order to record their time). Participants first pressed down on the spacebar so that stopping would require a passive response: lifting their finger off. The reason for this is that we wanted to make it easy to participants to quit, and people are more likely to quit if doing so requires a passive response rather

than an active response (Baumesiter et al., 1998). To measure their performance, their total number of responses (e’s crossed out) was subtracted by the number of errors they had made (e’s that should have been crossed out but were not and e’s that were crossed out but should not have been) (see Baumeister et al., 1998).

Participants were then given a questionnaire we created through discussion as a self-report measure of ego depletion: The Ego Depletion Questionnaire, which asked questions such as: “How fed up did you feel?”. Possible responses included 1: Not at all, 2: Slightly, 3: Quite, or 4: Very. This questionnaire has low internal consistency (Cronbach’s α = 0.545).

Participants were then asked questions during the suspicion and manipulation check before being debriefed. These checks assessed whether participants knew or suspected what was being tested and whether participants felt tempted or hungry during the manipulation.

ResultsThree 2 X 2 analyses of variance (ANOVAs) were performed to see the relations between a) condition, autonomy and performance, b) condition, autonomy and persistence, and c) condition, autonomy and self reported ego depletion. Unsupportive of the hypotheses, the condition was not found to make any difference in performance, persistence, or self-reported ego depletion. It was impossible to assess whether being autonomous acted as a protective factor against ego-depletion because the manipula-tion did not ego deplete participants. This suggests that the manipulation was not strong or salient enough to have a strong effect. Participants high in autonomy performed better (M=161.96) on the task compared to those lower in autonomy (M=77.59), F(1, 54)=8.386, p<.05 (Figure 1). Participants high in autonomy did not tend to persist significantly longer (M=15.54) than those low in autonomy (M=13.44), F(1,54)=1.84, p=.181.

Correlations were performed to see if any of the


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following variables were related: performance, persistence, self reported ego depletion, condition, autonomy, temptation and hunger. The self-report measure did not predict ego-depletion although it seems that performance and persistence were consistent with each other showing that these two measures measured the same construct, r=.567, p<.001. Autonomy level was found to be significantly related to performance, r=.415, p<.05. Thus, more autonomous participants tended to perform better on the task (Figure 2). Autonomy level was also found to be significantly associated with persistence, r=.305, p<.05. That is, participants higher in autonomy tended to persist for longer on the task. The condition was found to be significantly correlated with temptation, r=.421, p<.001, with those in the appetizing food condition having been more tempted than those in the non-appetizing food condition. Finally, those who were hungrier tended to be more tempted, r=.441, p<.001. Since many participants were not hungry (n=24) and so not tempted (n=37), this may help to explain why the manipulation did not seem to have the desired effect of ego depleting participants.

Exploratory analyses of correlations between the subscales of the TSRQ (autonomous, controlled and amotivation), performance, persistence, self reported

ego depletion, temptation and condition were performed. The more participants had controlled motivation, the worse they tended to perform on the e-hunting task (r=-.376, p<.05). Participants higher in controlled motivation also tended to report being more ego depleted (r=.311, p<.05). A partial correlation between autonomy and performance, controlling for persistence, was significant (r=.309, p<.05). This shows that those who were higher in autonomy performed better, even when the effects of persistence were controlled for.

DiscussionOverall, the results show that being autonomous can have clear and helpful benefits. Those higher in autonomous motivation were better able to perform on a task that required self control. As well, those high in autonomous motivation were also able to persist for longer during a task requiring self-control. That is, these people got fed up, or ego depleted, later than people with lower autonomy.

Autonomous DietingThe results suggest that autonomous people can perform better and persist for longer on tasks that require self-control, such as the e-hunting task. This better performance and persistence may generalize to


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to other tasks that require self-control, such as dieting. People with autonomous motivation may be better able to adhere to and maintain a diet. Research has indeed shown that people with autonomous motivation who were dieting attended diet meetings more often, lost more weight, exercised more after the diet program ended and showed greater maintained weight loss two years later (Williams, Grow, Freedman, Ryan, & Deci, 1996).

Turning controlled motivation into autonomous motivationThis may seem like bad news for people with controlled motivation, but there is still hope. Controlled motivation can become autonomous motivation. In order to turn one’s motivation into autonomous motivation, one must internalize one’s motivation. One may do this by thinking of ways a goal would benefit them personally, and by thinking of reasons why achieving that goal may be good for them. One could thereby turn controlled motivation (I want to eat healthy because I would feel guilty if I do not) into autonomous motivation (I want to eat healthy because I have carefully thought about it and believe it is very important for many aspects of my life) by thinking of reasons why something would be beneficial to them (Koestner, R., personal communica-tion: lecture notes, 2009). In this way, anyone is capable of being able to successfully achieve and maintain goals.

Limitations and DirectionsThis study had two main limitations. Firstly, the manipulation was not strong enough. In the future, researchers can address this limitation by making manipulations more salient. Baumeister et al. achieved this by having participants eat one type of food (either appetizing or not appetizing) while the other type was in front of them (1998). It is interesting to note that the condition designed to be appetizing in the present study did tempt participants significantly, although not enough to ego deplete them. A second limitation was the self-report measure of ego depletion. This measure had not been pilot tested

and was created through a discussion with the three researchers involved. Although this measure, along with persistence and performance, was meant to measure the same construct, the self-report measure did not correlate with the other two measures, show-ing that they were not actually measuring the same construct. Additionally, the ego depletion measure had low internal consistency, showing that the individual questions were not measuring the same construct and thereby invalidating the measure. The reason this measure was used was because the researchers were not able to find a previously tested self-report questionnaire that measured ego depletion. A validated self-report questionnaire assessing ego depletion should be created. However, there still remains the problem of awareness; it is possible that people are simply unaware of how ego depleted they are. If this were the case, a self report measure of ego depletion would not be useful for measuring ego depletion.

ConclusionThe present study confirms the reliability of previous studies and suggests avenues for new research. It was shown that people who have autonomous motivation are better able to persist and perform on tasks that require self-restraint. This finding has significant implications for society. Having autonomous motivation for a goal can increase people’s chances of achieving and maintaining their goals, from resisting appetizing food to maintaining a diet. Autonomous motivation may also help people achieve goals unrelated to dieting. Additionally, using information which can help transform controlled motivation into autonomous motivation can help people with any type of motivation increase the chances of achieving their goals. Autonomous motivation seems to be one of the keys to success in tasks requiring self-control.


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ReferencesBabcock, Glenys (2004). Canadians and Dieting. Retrieved from Ipsos News Center website: http://www.ipsos-na.com/ news/pressrelease.cfm?id=2318Baumeister, R.F. (2002). Yielding to temptation: Self-control fail ure, impulsive purchasing, and consumer behaviour. Journal of Consumer Research, 28 (4), 670-676. Baumeister, R.F., Bratslavsky, E., Muraven, M., & Tice, D.M. (1998). Ego depletion: Is the active self a limited resource? Journal of Personality and Social Psychology, 74 (5), 1252-1265. Baumeister, R.F., Vohs, K.D., & Tice, D.M. (2007). The strength model of self-control. Current Directions in Psychologi cal Science, 16 (6), 351-355. Ferguson, G.A. & Takane, Y. (2005). Statistical analysis in psy chology and education (6th ed.). Montreal, Canada: Mc Graw-Hill Ryerson Limited.Moller, A.C., Deci, E.L., & Ryan, R.M. (2006). Choice and ego-de pletion: The moderating role of autonomy. Personality and Social Psychology Bulletin, 32 (8), 1024-1036. Ryan, R.M. & Deci, E.L. (2008). Treatment Self-Regulation Questionnaire (TSRQ). Retrieved from Self-Determi nation Theory website: http://www.psych.rochester. edu/SDT/measures/hc_scales.phpVohs, K.D. & Heatherton, T.F. (2000). Self-regulatory failure: A resource-depletion approach. Psychological Science, 11 (3), 249-254. Williams, G.C., Grow, V.M., Freedman, Z.R., Ryan, R.M., & Deci, E.L. (1996). Motivational predictors of weight loss and weight-loss maintenance. Journal of Personality and So cial Psychology, 70 (1), 115-126.

Acknowledgements:

Research done in collaboration with Jason Fiumidinisi and Nico-lette Lambert.


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The Role of COMT in the Mediation of Schizophrenia

Sonia Hussain

AbstractSchizophrenia is a mental disorder characterized by disintegration of thought processes and of emotional responsiveness. The role of the catechol-O-methyltransferase (COMT) gene in the expression of schizophrenia has been widely studied but many researchers have found conflicting results. This article provides a review of the current literature. Support was found for the association of the COMT gene Val allele with poor working memory and this allele may lead to the ‘schizophrenic personality.’ The most encouraging finding is that structural MRI (sMRI) studies have shown abnormalities in morphology in numerous brain regions in schizophrenics (and their unaffected family members relative to unaffected controls). There also appears to be an epistatic effect between the COMT gene, the proline dehydrogenase (oxidase) 1 (PRODH) gene. The most robust link between the COMT gene and schizophrenia lies in the fact that a higher percentage of velocardiofacial syndrome (VCFS) patients have schizophrenia relative to the general population. Therefore although a few conclusions can be drawn regarding the role of the COMT gene in the expression of schizophrenia, much work remains to be done to get a better picture of the exact role this gene plays.

IntroductionSchizophrenia is a severe psychiatric disorder affecting approximately 1% of the general population. The factors contributing to schizophrenia have been widely studied over the past two decades. Many studies have reported that the gene that codes for catechol-O-methyltransferase (COMT) plays a role in the expression of schizophrenia (Williams, Owen & Donovan, 2007).

According to the Diagnostic and Statistical Manual of Mental Disorders Text Revision (DSM-IV-TR), schizophrenia is characterized by such symptoms as delusions, hallucinations, disorganized speech, disor-ganized or catatonic behaviour, and social/

occupational dysfunction. It is clear from family and twin studies that around 80% of the risk of developing schizophrenia can be explained by genetic factors (vanHaren et al., 2008). Vulnerability to schizophrenia is believed to be expressed along a continuum including milder variants of the disorder such as schizotypal personality disorder, with severity dependent on biopsychosocial factors (Lenzenweger, 2006). It is assumed that all of these expressions on the continuum share a common neurodevelopmental pathway with schizophrenia (Weinberger, 1987). Therefore, markers of vulner-ability and associated features should be detectable in patients with schizophrenia spectrum disorder and in

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nonpsychotic people identified as schizotypic, includ-ing first-degree relatives, patients identified using genetic risk markers, and people identified through psychometric measures (Lewandowski, 2007).

The COMT GeneCatechol-O-methyltransferase (COMT) is an enzyme that is involved in breaking down dopamine. The enzyme is coded by the COMT gene located, along with 47 other genes, on a fragment of chromosome 22q11.2. Two isoforms of COMT protein are widely studied. The soluble cytoplasmic (S-COMT) isoform predominates in most assayed tissues whereas in the brain, a longer membrane-bound form (MB-COMT) is more common. The COMT gene contains a common single nucleotide polymorphism (SNP) that leads to a valine/methionine (Val/Met) substitution at codons 108 and 158 of S-COMT and MB-COMT, respectively (Williams et al. 2007). The polymophism is usually referred to as the Val/Met locus but is also known by the reference sequence identification code rs4680 (previously known as rs165688). The Val variant results in a higher level of enzyme activity (leading to less dopamine in the synapse) than the Met variant (which leads to more dopamine in the synapse).

The COMT Gene and SchizophreniaAbnormal regulation of dopamine has long been implicated in the origin and development of schizo-phrenia. The COMT enzyme plays a role in dopamine regulation, especially in the prefrontal cortex (PFC) (Karoum, Chrapusta, & Egan 1994). The COMT enzyme plays a greater role where there are fewer dopamine transporters such as in the dopaminergic synaptic termini of the mesocortical and mesothalamic pathways (Williams, Owen et al., 2007). The importance of COMT for dopamine break-down in the PFC has been confirmed in COMT gene knockout mice and by the effects of dopamine on pharmacological inhibition of the COMT enzyme in humans (Williams et al., 2007). High levels of dopamine in limbic regions are implicated in positive symptoms of schizophrenia, and low levels in the prefrontal cortex are implicated in cognitive dysfunction and negative symptoms (Lewandowski,

2007). This face valid explanation has been physiologically proven, before the advent of gene mapping, by showing that COMT enzyme activity, measured in erythrocytes, was higher in schizophrenic patients than in control subjects (Floderus, Böök et al., 1981). In addition to functional explanations for association, deletion of 22q11 (where the COMT gene maps to) leads to a disorder associated with highly elevated risk for the development of psychosis including schizophrenia, making the COMT gene a positional candidate gene for schizophrenia (Williams et al., 2007).

The COMT Gene and Cognitive FunctioningPrefrontal Cortex FunctioningAbnormal function of the PFC is a prominent feature of schizophrenia and has been proposed as a trait marker for schizophrenia (Williams, Owen et al., 2007). The Val/Met locus is associated with indices of PFC function, with one study relating the Val and Met alleles of the COMT gene with two tasks: imitation and reversal learning. Met homozygotes, with increased synaptic dopamine, showed better acquisition of the imitation rule, while Val homozygotes, with less synaptic dopamine, showed poorer acquisition of the imitation rule (Williams et al., 2007).

Working MemoryDeficits of working memory are among the major cognitive impairments of schizophrenia (Silver, Feldman et al., 2003), and deficits of working memory have been correlated to the onset of symptoms of schizophrenia (Menon, Anagnoson et al., 2001; Nestor, Shenton et al., 1998). COMT enzyme inhibitors can improve working memory in rodents (Liljequist, Haapalinna et al., 1997) and in humans with Parkinson’s disease (Gasparini, Fabrizio et al., 1997). In schizophrenics, the COMT gene Val allele predicts performance deficits on working memory tasks such as the Wisconsin Card Sorting Test (Barnett, Jones et al., 2007; Egan, Goldberg et al., 2001; Joober, Gauthier et al., 2002; Lewandowski, 2007; Munafo, Bowes et al., 2005). However, the


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COMT gene Met allele is not associated with working memory (Goghari & Sponheim, 2008). Alternatively, the findings of another study that used the Wisconsin Card Sorting Test as well as other tests as measures of working memory and executive functions did not support a major role of the COMT gene in increasing susceptibility for schizophrenia or in mediating frontal lobe functioning (Ho, Wassink et al., 2005). These differing results can be explained by the fact that schizophrenia is a complex disorder with several interacting symptoms and epistatic effects. Another study has shown that haplotypes of the COMT gene show a stronger relationship with prefrontal inefficiency and working memory than did the Val/Met locus alone, suggesting that the COMT gene function is influenced by polymorphisms other than the Val/Met (Meyer-Lindenberg, Nichols et al., 2006). Further investigation of working memory, schizophrenia, and the COMT gene has supported the idea of epistasis in the heritability of schizophrenia (Tan, Callicott et al., 2009).

PersonalitySilberschmidt and Sponheim (2008) recently assessed relatives of schizophrenia patients on a questionnaire indicative of, among other things, cognitive deficit, a key feature of schizophrenia (Golimbet, 2008). They found abnormally low narcissism and rejectionality in Val homozygote relatives suggesting that the Val allele may be associated with an underdeveloped self-concept. Underdeveloped self-concept is similar to made volition (the feeling that some other force makes one do or say things that are not intended) and passivity, experiences comprising important symptoms of schizophrenia.

Endophenotypes of SchizophreniaSince no susceptibility genes with large effect sizes have been found yet, many studies have focused on testing specific genetic markers in the COMT gene for association with endophenotypes.

Structural NeuroimagingStructural MRI (sMRI) studies have repeatedly

shown abnormalities in morphology in numerous brain regions in schizophrenics and their unaffected family members relative to unaffected controls. The most consistently replicated findings are increased volumes of the lateral ventricles and decreased grey matter volume, particularly in frontal and medial temporal cortices (van Haren et al., 2008).

Cell Density of COMT in Differential Brain RegionsIt was originally thought that schizophrenia may involve increased COMT enzyme expression in glial cells in the frontal cortex; however, it has now been revealed that differential expression levels of COMT enzyme are not related to susceptibility to schizophrenia (Dempster, Mill et al., 2006).

P300 WavesP300 waves are event related potentials elicited by infrequent, task relevant stimuli. P300 wave anomalies can be correlated with genetic risk for schizophrenia (Bramon, Dempster et al., 2006) and research has found significant effects of the COMT gene genotype on frontal P300 amplitude. Lower frontal P300 amplitudes occurred in homozygous carriers of the Met allele, particularly in schizophrenic patients (Gallinat, Bajbouj et al., 2003; Golimbet, Gritsenko et al., 2006). More recently, however, it has been concluded that if there is an interaction between the COMT gene and P300 endophenotypes, it is a very subtle association (Bramon, Dempster et al., 2006).

The COMT Gene and PedigreesWu and colleagues (2003) investigated five pedigrees with high incidence of schizophrenia and found that the COMT gene is associated with schizophrenia in each of the five pedigrees. The results suggest that there might be a schizophrenia liability gene on chromosome 22 (22q11.2). Further family studies have been performed using haplotype analysis with

varying results (Handoko, Nyholt et al., 2004).


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The COMT Gene and Gene MappingVal108/158Met PolymorphismSeveral association studies have been done to show the link between the COMT gene and schizophrenia. The premise of these studies is genotyping a large sample of schizophrenics to see if they have a preferential allele of the Val108/158Met SNP (Table 1). Since the COMT gene Val108/158Met is so wide-ly studied, only the case controlled results involving schizophrenia or schizotypy were included although many of the referenced studies looked at family wide association and generally psychotic patients as well. Gender effects (Kremer, Pinto et al., 2003; Sazci, Ergul et al., 2004), violence/suicide implications (Han, Kee et al., 2006; Kotler, Barak et al., 1999;

Liou, Tsai et al., 2001; Nolan, Volavka et al., 2000; Strous, Bark et al., 1997), and the effects of treatment on severity of psychosis (Illi, Mattila et al. 2003; Molero, Ortuno et al. 2007) were not considered in this review. Altogether, these studies suggest that a single locus effect of the Val/Met polymorphism on schizophrenia risk is highly unlikely and that perhaps another polymorphism on the same chromosome is responsible.

Haplotype AnalysisHaplotype analysis was initially promising (Table 2), however, a recent meta-analysis of the common polymorphism (Val108/158Met) and haplotypes rs737865-rs165599 of the COMT gene concluded that it is unlikely that the COMT gene contributes to susceptibility to schizophrenia (Okochi, Ikeda et al.,


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Note: All studies are unique experimental studies except the ones marked REVIEW or META-ANALYSIS.

2009)

Epistatic and Gene x Environment InteractionsEpistatic EffectsIn contrast to simple Mendelian dominance, there is no reason to conclude that only one gene is responsible for a complex psychiatric disorder such as schizophrenia (Braff, Freedman et al., 2007). Many studies look at the effect of genes in response to treatment but these are beyond the scope of this paper. Several interactions have been tested (Muntjewerff, Gelleking et al., 2008; Nicodemus, Kolachana et al., 2007; Pelayo-Terán, Crespo-Facorro et al., 2008; Prata, Mechelli et al., 2009; Roffman, Gollub et al., 2008; Talkowski, Kirov et al., 2008; Tan, Callicott et al., 2009; Wang, Hu et al., 2008; Xu, Kellendonk et al., 2007) with the most promising epistatic effect being found between the COMT gene and the proline dehydrogenase (oxidase) 1 (PRODH)

gene, another candidate gene for schizophrenia with studies providing varying support for mice (Paterlini, Zakharenko et al., 2005) and for humans (Zinkstok, Schmitz et al., 2008). These studies used microarray analysis and quantitative reverse transcription poly-merase chain reaction (RT-PCR) (Jurata, Gallagher et al., 2006).

Gene x Environment InteractionsCaspi and colleagues (Caspi, Moffitt et al., 2005) found that adult carriers of the COMT gene Val allele were most likely to exhibit psychotic symptoms and to develop schizophreniform disorder if they used cannabis, whereas cannabis use had no such adverse influence on individuals with 2 copies of the Met allele. However the findings of this study have not been replicated (Henquet, Di Forti et al. 2008; Zammit, Spurlock et al., 2007).

22q11 Deletion SyndromeA microdeletion syndrome, in which 22q11 deletion syndrome maps to 22q11.2, encompasses


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Note that rs4680 = rs165688Note that a yes/no in the significant association column refers to a significant relationship between the specific COMT haplotype studied and schizophrenia.

several conditions including velocardiofacial syndrome (VCFS) (Lewandowski, 2007). The majority of cases of VCFS fulfill the diagnostic criteria for schizophrenia or schizoaffective disorder (24% of one sample (Murphy, Jones et al., 1999) and 100% of another sample (Xu, Roos et al., 2008)). Investigations into differential allele effects show that for individuals with 22q11 deletion syndrome, risk of psychosis was increased in individuals who were hemizygous for the Met allele (more dopamine in synapse) (Raux, Bumsel et al., 2007). These results are also supported by haplotype analysis (Sanders, Rusu et al., 2004). Despite some studies claiming that 22q11.2 deletion does not contribute substantially to the development of schizophrenia in general (Arinami, Ohtsuki et al., 2001; Bassett, Caluseriu et al., 2007), 22q11DS is the strongest link to date be-tween vulnerability to schizophrenia and the COMT gene (Lewandowski, 2007).

ConclusionsBecause of its function and position, and support for its genetic variation influencing the susceptibility of schizophrenia, the COMT gene has become one of the most studied genes in psychiatric disorders (Williams, Owen et al., 2007). This review provides support for the association of the COMT gene Val allele with poor working memory, specifically when measured using the WCST. More recent research by Silberschmidt and Sponheim (2008) suggests that the Val allele of the COMT gene may lead to the ‘schizophrenic personality’. The most promising endophenotype, however, appears to be sMRI. After extensive research, gene mapping studies show that SNP or haplotype effects are unlikely, suggesting that epistatic effects, with the most promising epistatic effect being that between the COMT gene and the PRODH gene and the environment. The strongest link between the COMT gene and schizophrenia lies in the fact that a higher percentage of VCFS have schizophrenia relative to the general population. Further research needs to focus on these areas of interest, using a more systematic approach to reporting data.

ReferencesArinami, T., T. Ohtsuki, K. Takase, H. Shimizu, T. Yoshikawa, H. Horigome, J. Nakayama, and M. Toru. (2001). “Screening for 22q11 deletions in a schizophrenia population.” Schizophrenia Research 52(3): 167-170.Barnett, J. H., P. B. Jones, T.W. Robbins, and U. Muller (2007). “Effects of the catechol-O-methyltransferase Val 158Met polymorphism on executive function: a meta- analysis of the Wisconsin Card Sort Test in schizophrenia and healthy controls.” Mol Psychiatry 12(5): 502-509.Bassett, A. S., O. Caluseriu, R. Weksberg, D.A. Young, and E.W. Chow (2007). “Catechol-O-methyl Transferase and Expression of Schizophrenia in 73 Adults with 22q11 Deletion Syndrome.” Biological Psychiatry 61(10): 1135-1140.Braff, D. L., R. Freedman, N.J. Schork, and I.I. Gottesman (2007). “Deconstructing Schizophrenia: An Overview of the Use of Endophenotypes in Order to Understand a Complex Disorder.” Schizophr Bull 33(1): 21-32.Bramon, E., E. Dempster, S. Frangou, C. McDonald, P. Schoenberg, J.H. MacCabe, M. Walshe, P. Sham, D. Collier, and R.M. Murray (2006). “Is there an association between the COMT gene and P300 endophenotypes?” European Psychiatry 21(1): 70-73.Caspi, A., T. E. Moffitt, M. Cannon, J. McClay, R. Murray, H. Harrington, A. Taylor, L. Arsenault, B. Williams, A. Braithwaite, R. Poulton, and I.W. Craig (2005). “Moderation of the Effect of Adolescent-Onset Cannabis Use on Adult Psychosis by a Functional Polymorphism in the Catechol-O-Methyltransferase Gene: Longitudinal Evidence of a Gene X Environment Interaction.” Biological Psychiatry 57(10): 1117-1127.Dempster, E., J. Mill, I.W. Craig, D.A. Collier (2006). “The quantification of COMT mRNA in post mortem cere- bellum tissue: diagnosis, genotype, methylation and ex pression.” BMC Medical Genetics 7(1): 10.Egan, M. F., T. E. Goldberg, B.S. Koalchana, J.H. Callicott, C.M. Mazzanti, R.E. Straub, D. Goldman, and D.R. Weinberger (2001). “Effect of COMT Val108/158 Met genotype on frontal lobe function and risk for schizophrenia.” Proceedings of the National Academy of Sciences of the United States of America 98(12): 6917- 6922.Floderus, Y., J. A. Böök, and L. Wetterberg (1981). “Erythrocyte catechol-O-methyltransferase activity in related families with schizophrenia.” Clinical Genetics 19(5): 379-385.Gallinat, J., M. Bajbouj, T. Sander, P. Schlattmann, K. Xu, E.F. Ferro, D. Goldman, and G. Winterer (2003). “Association of the G1947A COMT (Val108/158Met) gene polymorphism with prefrontal P300 during information processing.” Biological Psychiatry 54(1): 40-48.


18

Gasparini, M., E. Fabrizio, V. Bonifati, and G. Meco (1997). “Cognitive improvement during Tolcapone treatment in Parkinson’s disease.” Journal of Neural Transmis- sion 104(8): 887-894.Goghari, V. M. and S. R. Sponheim (2008). “Divergent backward masking performance in schizophrenia and bipolar disorder: Association with COMT.” American Journal of Medical Genetics Part B: Neuropsychiatric Genetics 147B(2): 223-227.Golimbet, V. (2008). “Molecular genetic studies of cognitive defi cit in schizophrenia.” Molecular Biology 42(5): 738-746.Golimbet, V., I. Gritsenko, M. Alfimova, I. Lebedeva, T. Lezheiko, L. Abramova, V. Kaleda, and R. Ebstein (2006). “Association study of COMT gene Val158Met polymorphism with auditory P300 and performance on neurocognitive tests in patients with schizophrenia and their relatives.” World Journal of Biological Psychiatry 7(4): 238 - 245.Han, D. H., B.S. Kee, K.J. Min, Y.S. Lee, C. Na, D.B. Park, and I.K. Lyoo (2006). “Effects of catechol-O-methyltransferase Val158Met polymorphism on the cognitive stability and aggression in the first-onset schizophrenic patients.” Neuroreport 17(1): 95-99.Handoko, H. Y., D. R. Nyholt, N.K. Hayward, D.A. Nertney, D.E. Hannah, L.C. Windus, C.M. McCormack, H.J. Smith, C. Filippich, M.R. James, B.J. Mowry (2004). “Separate and interacting effects within the catechol-O- methyltransferase (COMT) are associated with schizophrenia.” Mol Psychiatry 10(6): 589-597.Henquet, C., M. Di Forti, P. Morrison, R. Kuepper, and R.M. Murray (2008). “Gene-Environment Interplay Between Cannabis and Psychosis.” Schizophr Bull 34(6): 1111- 1121.Ho, B. C., T. H. Wassink, D.S. Leary, V.C. Sheffield, N.C. Andreasen (2005). “Catechol-O-methyl transferase Val 158Met gene polymorphism in schizophrenia: working memory, frontal lobe MRI morphology and frontal cerebral blood flow.” Mol Psychiatry 10(3): 287-298.Illi, A., K.M. Mattila, O. Kampman, S. Anttila, M. Roivas, T. Lehtimaki, and E. Leinonen. (2003). “Catechol-O-methyltransferase and Monoamine Oxidase A Genotypes and Drug Response to Conventional Neuroleptics in Schizophrenia.” Journal of Clinical Psychopharmacol- ogy 23(5): 429-434.Joober, R., J. Gauthier, S. Lal, D. Bloom, P. Lalonde, G. Rouleau, C. Benkelfat, and A. Labelle (2002). “Catechol-O-Meth- yltransferase Val-108/158-Met Gene Variants Associated With Performance on the Wisconsin Card Sorting Test.” Arch Gen Psychiatry 59(7): 662-663.Jurata, L. W., P. Gallagher, A.L. Lemire, V. Charles, J.A. Brock- man, E.L. Illingworth, and C.A. Altar (2006). “Al- tered expression of hippocampal dentate granule neuron genes in a mouse model of human 22q11 deletion syndrome.” Schizophrenia Research 88(1-3): 251- 259.

Karoum, F., S.J. Chrapusta, and M. F. Egan (1994). “3-Methoxy tyramine Is the Major Metabolite of Released Dopa- mine in the Rat Frontal Cortex: Reassessment of the Effects of Antipsychotics on the Dynamics of Dopa- mine Release and Metabolism in the Frontal Cortex, Nucleus Accumbens, and Striatum by a Simple Two Pool Model.” Journal of Neurochemistry 63(3): 972-979.Kotler, M., P. Barak, H. Cohen, I.E. Averbuch, A. Grinshpoon, I. Gritsenko, L. Nemanov, and R.P. Ebstein (1999). “Homicidal behavior in schizophrenia associated with a genetic polymorphism determining low catechol O- methyltransferase (COMT) activity.” American Journal of Medical Genetics 88(6): 628-633.Kremer, I., M. Pinto, I. Murad, M. Muhaheed, I. Bannoura, D.J. Muller, T.G. Schulze, A. Reshef, M. Blanaru, S. Gathas, R. Goichman, M, Rietschel, M. Dobrusin, R. Bachner-Melman, L. Nemanov, R.H. Belmaker, W. Maier, and R.P. Ebstein (2003). “Family-based and case-control study of catechol-O-methyl transferase in schizophrenia among Palestinian Arabs.” American Journal of Medical Genetics Part B: Neuro- psychiatric Genetics 119B(1): 35-39.Lenzenweger, M. F. (2006). “Schizotaxia, schizotypy, and schizophrenia: Paul E. Meehl’s blueprint for the experimental psychopathology and genetics of schizophrenia.” Journal of Abnormal Psychology 115(2): 195-200.Lewandowski, K. E. (2007). “Relationship of Catechol-O-Meth- yltransferase to Schizophrenia and Its Correlates: Evidence for Associations and Complex Interactions.” Harvard Review of Psychiatry 15(5): 233-244.Liljequist, R., A. Haapalinna, M. Ahlander, Y.H. Li, and P.T. Mannisto (1997). “Catechol 0-methyltransferase inhibitor tolcapone has minor influence on performance in experimental memory models in rats.” Behavioural Brain Research 82(2): 195-202.Liou, Y. J., S. J. Tsai, C.J. Hong, Y.C. Wang, I.C. Lai (2001). “Association Analysis of a Functional Catechol-O- Methyltransferase Gene Polymorphism in Schizo- phrenic Patients in Taiwan.” Neuropsychobiology 43(1): 11-14.Menon, V., R. T. Anagnoson, D.H. Mathalon, G.H. Glover, A. Pfefferbaum (2001). “Functional Neuroanatomy of Auditory Working Memory in Schizophrenia: Relation to Positive and Negative Symptoms.” NeuroImage 13(3): 433-446.Meyer-Lindenberg, A., T. Nichols, J.H. Callicott, J. Ding, B. Kolachana, J. Buckholtz, V.S. Mattay, M. Egan, and D.R. Weinberger (2006). “Impact of complex genetic variation in COMT on human brain function.” Mol Psychiatry 11(9): 867-877.Molero, P., F. Ortuno, M. Zalacain, and A. Patino-Garcia (2007). “Clinical involvement of catechol-O-methyltransferase polymorphisms in schizophrenia spectrum disorders: influence on the severity of psychotic symptoms and on the response to neuroleptic treatment.” Pharmacoge


19

nomics J 7(6): 418-426.Munafo, M. R., L. Bowes, T.G. Clark, J. Flint (2005). “Lack of association of the COMT (Val158//108 Met) gene and schizophrenia: a meta-analysis of case-control studies.” Mol Psychiatry 10(8): 765-770.Muntjewerff, J.-W., H. Gellekink, M. denHeijer, M.L. Hoogendoorn, R.S. Kahn, R.J. Slinke, and H.J. Blom (2008). “Polymorphisms in catechol-O-methyltransferase and methylenetetrahydrofolate reductase in relation to the risk of schizophrenia.” European Neuropsycho- pharmacology 18(2): 99-106.Murphy, K. C., L. A. Jones, and M.J. Owen (1999). “High Rates of Schizophrenia in Adults With Velo-Cardio-Facial Syndrome.” Arch Gen Psychiatry 56(10): 940-945.Nestor, P. G., M. E. Shenton, C. Wible, H. Hokama, B.F. O’Donnell, S. Law, R.W. and McCarley (1998). “A neuropsychological analysis of schizophrenic thought disorder.” Schizophrenia Research 29(3): 217-225.Nicodemus, K., B. Kolachana, R. Vakkalanka, R.E. Straub, I. Giegling, M.F. Egan, D. Rujescu, D.R. Weinberger (2007). “Evidence for statistical epistasis between catechol-O-methyltransferase (COMT) and polymorphisms in RGS4, G72 (DAOA), GRM3, and DISC1: influence on risk of schizophrenia.” Human Genetics 120(6): 889-906.Nolan, K. A. a., J. a. Volavka, P. Czobor, A. Cseh, H. Lachman, T. Saito, J. Tiihonen, A. Putkonen, T. Hallikainen, I. Kotilainen, P. Rasanen, M. Isohanni, M.R. Jarvelin, and M.K. Karvonen (2000). “Suicidal behavior in patients with schizophrenia is related to COMT polymorphism.” Psychiatric Genetics 10(3): 117-124.Okochi, T., M. Ikeda, T. Kishi, K. Kawashima, Y. Kinoshita, T. Kitajima, Y. Yamanouchi, M. Tomita, T. Inada, N. Ozaki, N. Iwata (2009). “Meta-analysis of association between genetic variants in COMT and schizophrenia: An update.” Schizophrenia Research 110(1-3): 140-148.Paterlini, M., S. S. Zakharenko, W.S. Lai, J. Qin, H. Zhang, J. Mukai, K.G. Westphal, B. Olivier, D. Sulzer, P. Pavlidis, S.A. Siegelbaum, M. Karayiorgou, and J.A. Gogos (2005). “Transcriptional and behavioral interaction between 22q11.2 orthologs modulates schizophrenia-related phenotypes in mice.” Nature Neuroscience 8(11): 1586- 1594.Pelayo-Terán, J. M., B. Crespo-Facorro, E. Carrasco-Marin, R. Perez-Iglesias, I. Mata, M.J. Arranz, F. Leyva-Cobian, a nd J.L. Vazquez-Barquero. (2008). “Catechol-O-methyltransferase Val158Met polymorphism and clinical characteristics in first episode non- affective psychosis.” American Journal of Medical Genetics Part B: Neuropsychiatric Genetics 147B(5): 550-556.Prata, D. P., A. Mechelli, C.H. Fu, M. Picchioni, T. Toulopoulou, E. Bramon, M. Walshe, R.M. Murray, D.A. Collier, and P. McGuire (2009). “Epistasis between the DAT 3â€² UTR VNTR and the COMT Val158Met SNP on

cortical function in healthy subjects and patients with schizophrenia.” Proceedings of the National Academy of Sciences 106(32): 13600-13605.Raux, G., E. Bumsel, B. Hecketsweiler, T. van Amelsvoort, J. Zinstok, S. Manouvrier-Hanu, C. Fantini, G.M. Breviere, G. Di Rosa, G. Pustorino, A. Vogels, A. Swillen, S. Legallic, J. Bou, G. Opolczynski, V. Drouin- Garraud, M. Lemarchand, N. Philip, A. Gerard- Desplanches, M. Carlier, A. Philippe, M.C. Nolen, D. Heron, P, Sarda, D. Lacombe, C. Coizet, Y. Alembik, V. Layet, A. Afenjar, D. Hannequitn, C. Demily, M. Petit, F. Thibault, T. Frebourg, and D. Campion (2007). “ Involvement of hyperprolinemia in cognitive and psychiatric features of the 22q11 deletion syndrome.” Hum. Mol. Genet. 16(1): 83-91.Roffman, J. L., R. L. Gollub, V.D. Calhoun, T.H. Wassink, A.P. Weiss, B.C. Ho, T. White, V.P. Clark, J. Fries, N.C. Andreasen, D.C. Goff, D.S. Manoach (2008). “MTHFR 677C â†’ T genotype disrupts prefrontal function in schizophrenia through an interaction with COMT 158Val â†’ Met.” Proceedings of the National Academy of Sciences 105(45): 17573-17578.Sanders, A. R., I. Rusu, J. Duan, J.E. Vander Molen, C. Hou, S.G. Schwab, D.B. Wildenauer, M. Martinez, P.V. Gejman (2004). “Haplotypic association spanning the 22q11.21 genes COMT and ARVCF with schizophrenia.” Mol Psychiatry 10(4): 353-365.Sazci, A., E. Ergul, I. Kucukali, G. Kilic, G. Kaya, I. Kara (2004). “Catechol-O-methyltransferase gene Val108/158Met polymorphism, and susceptibility to schizophrenia: association is more significant in women.” Molecular Brain Research 132(1): 51-56.Silberschmidt, A. L. and S. R. Sponheim (2008). “Personality in relation to genetic liability for schizophrenia and bipolar disorder: Differential associations with the COMT Val108/158Met polymorphism.” Schizophrenia Research 100(1-3): 316-324.Silver, H., P. Feldman, W. Bilker, R.C. Gur (2003). “Working Memory Deficit as a Core Neuropsychological Dysfunction in Schizophrenia.” Am J Psychiatry 160(10): 1809-1816.Strous, R. D., N. Bark, M. Woerner, H.M. Lachman (1997). “Lack of association of functional cathechol-O-methyltransferase gene polymorphism in schizophrenia.” Biological Psychiatry 41(4): 493-495.Talkowski, M. E., G. Kirov, M. Bamne, L. Georgieva, G. Torres, H. Mansour, K.V. Chowdari, V. Milanova, J. Wood, L. McClain, K, Prasad, B. Shirts, J. Zhang, M.C. O’Donovan, M.J. Owen, B. Devlin, V.L. Nimgaonkar (2008). “A network of dopaminergic gene variations implicated as risk factors for schizophrenia.” Hum. Mol. Genet. 17(5): 747-758.Tan, H.-Y., J. H. Callicott, and D.R. Weinberger (2009). “Prefrontal cognitive systems in schizophrenia : Towards human genetic brain mechanisms.” Cognitive


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Neuropsychiatry 14(4): 277 - 298.van Haren, N. E., S. C. Bakker, and R.S. Kahn. (2008). “Genes and structural brain imaging in schizophrenia.” Current Opinion in Psychiatry 21(2): 161-167.Wang, Y., Y. Hu, Y. Fang, K. Zhang, H. Yang, J. Ma, Q. Xu, and Y. Shen (2009). “Evidence of Epistasis Between the Catechol-O-Methyltransferase and Aldehyde Dehydrogenase 3B1 Genes in Paranoid Schizophrenia.” Biological Psychiatry 65(12): 1048-1054.Weinberger, D. R. (1987). “Implications of Normal Brain Development for the Pathogenesis of Schizophrenia.” Arch Gen Psychiatry 44(7): 660-669.Williams, H. J., M. J. Owen, and Donovan (2007). “Is COMT a Susceptibility Gene for Schizophrenia?” Schizophr Bull 33(3): 635-641.Wu, H. A., X.M. Deng, X.H. Yan, T.B. Liu, J.Z. Hu, H. Gao, Q.J. Shen (2003). “Association study of five pedigree with high incidence of schizophrenia.” Yi Chuan 25(6): 652- 654.Xu, B., J. L. Roos, S. Levy, E.J. van Rensburg, J.A. Gogos, M. Karayiorgou (2008). “Strong association of de novo copy number mutations with sporadic schizophrenia.” Nat Genet 40(7): 880-885.Xu, H., C. B. Kellendonk, E.H. Simpson, J.G. Keilp, G.E. Bruder, H.J. Polan, E.R. Kandel, T.C. Gilliam (2007). “DRD2 C957T polymorphism interacts with the COMT Val158Met polymorphism in human working memory ability.” Schizophrenia Research 90(1-3): 104- 107.Zammitt, S., G. Spurlock, H. Williams, N. Norton, N. Williams, M.C. O’Donovan, and M.J. Owen (2007). “Genotype effects of CHRNA7, CNR1 and COMT in schizophrenia: interactions with tobacco and cannabis use.” The British Journal of Psychiatry 191(5): 402-407.Zinkstok, J., N. Schmitz, T. van Amelsvoort, M. Moeton, F. Baas, and D. Linszen (2008). “Genetic variation in COMT and PRODH is associated with brain anatomy in patients with schizophrenia.” Genes, Brain and Behavior 7(1): 61-69.


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Cooking Up Creativity: A critical analysis of The Talent Code: Greatness Isn’t Born. It’s

Grown. Here’s How. By Daniel Coyle

Leora Frimer

AbstractWhere does expert talent come from? Some argue that it is a mixture of both environmental and innate factors, while others take a polarized approach in understanding expertise, and either argue that it is innate or purely guided by motivational factors. Daniel Coyle’s book, “The Talent Code”, argues that expertise stems from a number of factors, and that with a certain amount and type of practice, expertise may be achieved. Acclaimed artist Linda Frimer exemplifies an exception to this talent code, demonstrating the innate, unique aspect to a certain type of expertise. Therefore, unique expertise stems from innate factors in addition to practice.

Although many enjoy painting, few establish them-selves as professional artists and form careers on this basis. Born in the wilderness of northern British Columbia, acclaimed artist Linda Frimer, is one of these few. She creates aesthetically moving paintings that Paul George, founding director of the Western Canada Wilderness committee, claims strike “emotional chords in people where real change occurs” (“About Linda Frimer,” 2011). Her work has been used to raise funds for wilderness pres-ervation and breast cancer research, among other causes. According to psychologist Anders Ericsson, Frimer should be considered an expert as she dem-onstrates consistently superior performance in the

artistic realm of painting. In his book, The Talent Code: Greatness Isn’t Born. It’s Grown. Here’s How, Daniel Coyle claims that talent is not innate, but can be developed (2009). Coyle uses this argument to ex-plain expertise in fields that span from neurology to coaching techniques. Based on his field research of nine of the world’s greatest hotbeds, or locations of talent, Coyle connects information about features of the brain with observations of methods of practice and effective coaching to produce the talent code. A traditional notion is that talent is innate and that what separates experts from non-experts is ability. Coyle opposes this conception with the idea that talent can be developed in a certain way. This paper

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willcritically analyze the arguments Daniel Coyle presents in his book The Talent Code: Greatness Isn’t Born. It’s Grown. Here’s How, employing artist Linda Frimer as an example of expert talent to illustrate both the strengths and weaknesses of his argument.

A compelling component of Coyle’s argument is his focus on the importance of deep practice, a type of practice that separates experts from non-experts. The mechanisms that underlie deep practice might be considered paradoxical, but in effect, translate to growth in talent in a domain. This paradox is the struggle of operating at the edge of our abilities, and the mistakes that, in actuality, lead us to improve-ment. When one practices deeply, time is used more efficiently and small efforts lead to lasting results. The more we develop a skill circuit, the less we are aware that we are using it. Anders Ericsson supports this argument, highlighting the necessity of Coyle’s version of deep practice, deliberate practice. Ericsson, in line with Coyle’s argument, notes that expertise in a field results from ten thousand hours of dedicated practice (Ericsson, 1994). The practice Ericsson and Coyle refer to is of a particular type, involving work-ing on one’s technique, seeking constant critical feed-back and focusing on fixing weaknesses. This type of practice is not merely repeating activity, but doing an activity repeatedly in a targeted manner that drives improvement. Coyle’s deep practice includes four constituents: a goal to improve performance, clear instructions on how to improve, immediate feedback on performance, and the repetition of similar tasks. Artist Linda Frimer employs deep practice and is well known for the luminosity she achieves using the me-dium of watercolour. Each time she approaches the medium, she is aware that she can never completely control the amount of water, the intensity of color on her brush, and drying time, and thus continuously makes mistakes; however, these mistakes allow her to develop her artistic talent as they often add expres-sion to the work (personal communication, November 20, 2010).

The greatest strength of Coyle’s argument is that he supports it with scientific evidence. He sketches a picture of the neurophysiology of learning and this

is an image that few others have attempted to draw. His argument is based on myelin, a substance that insulates neurons, preventing electrical impulses from leaking out. The more we practice, the more insulated our neural circuits become, increasing the speed and accuracy of our movements. Coyle notes that there is a relationship between skill and the amount of my-elin insulation that wraps neural circuits. There are critical periods during which the brain is especially receptive to learning new skills and this is a possible reason why the vast majority of those that become experts begin practicing at a young age (Coyle, 2009). Coyle argues that one must have ignition, a pas-sion that is necessary for hard work and thus myelin growth. This ‘ignition’ motivates people to invest thousands of hours of deliberate practice, drawing them closer to their vision of the expertise they want to achieve.

Psychology professor Csikszentmihalyi’s research on flow further strengthens Coyle’s model. Flow is a state characterized by clear goals, immediate feed-back, a match of challenge and skill, absorption in the task, a sense of personal control, and an altered sense of time (Csikszentmihalyi, 1992). Deliberate practice fosters flow, and many experience flow dur-ing a leisure activity that requires a specific set of skills. Csikszentmihalyi’s (1992) prospective longitu-dinal study on flow demonstrates that it is a type of deliberate practice, and that those who spend more time in flow activities continue to develop their talent years later. Thus, a key factor associated with talent development is that a flow experience increases the likelihood of continual development of skills. Linda Frimer, who describes her experience of painting as a flow of energy, shows the importance of flow in increasing skill level and gaining expertise. Her goals are clear, she has immediate feedback as she observes the canvas, and she becomes absorbed in the task to a point where, for her, the notion of time seems to dis-appear and she sometimes finds herself painting for hours (personal communication, November 20, 2010). Her experience of what Csikszentmihalyi calls ‘flow’ results in her expertise.

Additional support for Coyle’s model comes from


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research on the environment a child was raised in. Benjamin Bloom (1985) found clear similarities in how experts describe their early upbringing. The childhood home environments of experts tend to be child-, achievement-, and responsibility-oriented, strengthening the notion that environment is an important factor in determining expert performance. Born in the wilderness, Linda Frimer spent her early years outdoors, often playing alone, absorbed by what she refers to as the wonder of the natural beauty surrounding her, and this is where her inspiration began (personal communication, November 20, 2010).

Research by Ericsson and Charness supports Coyle’s argument for the importance of childhood upbring-ing, influencing expertise. They argue that if parents express interest in a task, it will positively reinforce their child. Frimer grew up surrounded by fashion sketches done by her mother. Her mother’s drawing tools were always made available to her, and she used them frequently. Therefore skill might be the result of a combination of early exposure to art and train-ing, rather than innate talent.

Despite the evidence in support of Coyle’s model, some limitations exist. Coyle argues that, while deep practice and ignition are required, a third ingredient is necessary to produce talent: master coaching. Coyle refers to the profusion of artistic talent in Florence during the Renaissance to exemplify the requirement of master coaching in producing talent. Guilds were based on the apprenticeship system, which enabled individuals from an early age to learn the craft from a master through mentorship and action, involving the actual mixing of paint and preparation of can-vases rather than merely textbook-learning. This one-on-one method of learning by example is the justification Coyle provides for the abundance of ar-tistic talent during this period in history. Despite the plausibility of his argument, it suffers in the difficulty of its application to all examples of talent, includ-ing Linda Frimer. Frimer established her career long before she had any form of master coaching. Indeed, her murals had been hung in public domains and she had important works commissioned in public build-ings long before she received any formal training. She

deliberately practiced out of enjoyment and awe for the natural beauty of the wilderness that surrounded her, which was her inspiration, and it was her love of art that propelled her to self-instruct. This autonomous inspiration contributes to her expertise.

Another shortcoming of Coyle’s argument is that it is reductionist. His argument focuses solely on a newly discovered mechanism in the brain through which skill is acquired. This narrow focus on our actions and its effects on the brain is too narrow. There are important implications of this reductionist flavour that result in the question: are ten thousand hours of practice realistic or verging on excessive? As well, Coyle fails to explain where the ignition and interest comes from in the first place. Linda Frimer’s mother, who was accepted to a top fashion school in New York during the depression, was creative also, as was her aunt who was a well-known hat designer in New York. Perhaps there is some genetic component that Coyle fails to further explore.

Professor Ellen Winner presents compelling research that weakens Coyle’s argument. In her study on gifted mathematicians and musicians, she finds atypical brain organization involving superior visual spatial abilities, non-right-handedness, and more bi-lateral brain organization (Winner, 2000). Interestingly, art-ist Linda Frimer is left-handed. Whether this sup-ports Winner’s argument or not, it is interesting to note the biological difference that are perhaps results of genetic variations.

It is difficult to use Coyle’s argument to explain Linda Frimer’s talent which depends largely on imagina-tion and innovation. He discusses how one can make a neural circuit more efficient, through deep practice, which would be extremely beneficial for mechanical, automatic activities low on creativity, but not necessarily for more creative activities. Much of his book concentrates on activities such as sports and chess, activities that can be learned over time, and activities for which the argument of the benefit of deliberate practice seems plausible. Despite his


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not the creation of one’s own unique artistic vision. It is in this way that Coyle’s argument fails to address the origins of certain talents, for example Linda Frimer’s.

Ultimately, one must be careful not to assume that Coyle’s recipe for talent is universally plausible. The importance of deep practice, the significance of myelin and its relationship to deep practice, and the importance of ignition are strengths of his argument that have been demonstrated in numerous examples. However, not all of the requirements for talent that he suggests are applicable to all individuals. This has been exemplified by artist Linda Frimer, who had no master coaching prior to establishing herself as a professional artist. Although she deliberately practiced, and had a strong and autonomous motiva-tion to draw and paint, master coaching was not a necessary ingredient for her recipe to success, and it was not until after she had established her career that she decided to attend art school to obtain a degree. To more clearly understand causality, researchers may wish to further explore the relationships between environment, biology, and talent. For example, one might conduct a longitudinal study on children adopted at birth, who therefore were not living under the influential environment of their genetic parents, and investigate to what extent the talents they develop are influenced by the environ-ment in which they grow or whether there is some resemblance to their genetic parents’ interests. Frimer and her two siblings were raised in the same environment, yet it was only she who became a professional artist. The origin of her spark of creative passion is the missing ingredient in Coyle’s recipe for talent.

Disclaimer: Please note that Linda Frimer is related to the author of this paper. After reviewing the paper, the editors have agreed that the author’s relationship to Linda Frimer has not affected the author’s analysis.

ReferencesCoyle, D. (2009). The talent code: Greatness isn’t born : it’s grown, here’s how. New York: Bantam Books. Csikszentmihalyi M., and Rathunde K. (1992). “The Measurement of flow in everyday life: toward a theory of emergent motivation”. Ericsson, K. Anders, and Charness, Neil. (1994). “Expert Performance. It’s Structure and Acquisition”. American Psychologist. (n.d) About Linda Frimer. Retrieved from http://lindafrimer.ca/ about-2/ Winner, Ellen. (2000). “The Origins and Ends of Giftedness”. American Psychologist.


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Crosslinguistic Influence on Argument Realization in Japanese-

English Bilinguals

David Atia

AbstractCrosslinguistic influence in simultaneous bilinguals has been widely reported in various linguistic domains. Past research on crosslinguistic influence has led to the hypothesis that structures that involve the syntax–pragmatics interface and display a surface overlap between a bilingual’s two spoken languages are more vulnerable to crosslin-guistic influence (Müller & Hulk, 2001). This hypothesis has been extended by Serratrice, Sorace, and Paoli (2004) with the proposition that after the C-domain has been instantiated, pragmatic errors will be made at the syntax-pragmatics interface, rather than grammatical ones. A recent study by Blais, Oshima-Takane, Genesee, and Hiraka-wa (2010) revealed bi-directional crosslinguistic influence in older Japanese-French bilingual children, supporting the Serratrice et al. (2004) hypothesis. The present study sought to replicate these results with Japanese-English bilinguals, a novel language combination, using the same laboratory procedures and tasks. Mean proportions of the argument realizations of 13 bilinguals (aged 4 to 6) were compared with those of respective monolingual counter-parts in order to ascertain the existence of crosslinguistic effects. Contrary to predictions, no transfer effects were found in either direction. These findings point to both linguistic community and language dominance as possible additional factors underlying crosslinguistic influence.

IntroductionCrosslinguistic influence in simultaneous bilinguals has been widely reported in various linguistic do-mains. Past research on crosslinguistic influence has led to the hypothesis that structures that involve the syntax–pragmatics interface and display a surface overlap between a bilingual’s two spoken languages are more vulnerable to crosslinguistic influence (Müller & Hulk, 2001). This hypothesis has been extended by Serratrice, Sorace, and Paoli (2004) with the proposition that after the C-domain has been instantiated, pragmatic errors will be made at the syntax-pragmatics interface, rather than grammati-cal ones. A recent study by Blais, Oshima-Takane, Genesee, and Hirakawa (2010) revealed bi-direction-

al crosslinguistic influence in older Japanese-French bilingual children, supporting the Serratrice et al. (2004) hypothesis. The present study sought to repli-cate these results with Japanese-English bilinguals, a novel language combination, using the same labora-tory procedures and tasks. Mean proportions of the argument realizations of 13 bilinguals (aged 4 to 6) were compared with those of respective monolingual counterparts in order to ascertain the existence of crosslinguistic effects. Contrary to predictions, no transfer effects were found in either direction. These findings point to both linguistic community and language dominance as possible additional factors underlying crosslinguistic influence.

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The presence of bilingualism in many children has raised multiple questions for researchers studying language development. Bilingualism is the norm in many parts of the world, and it exists in several other unique contexts as well, such as when coloniza-tion imposes a new language on a country or when a school has a language immersion program. The very fact that bilingualism occurs both naturally and universally has caused several issues to surface in the relevant literature. The literature draws a distinc-tion between two types of bilingualism: simultane-ous and sequential (also known as second language bilingualism). Simultaneous bilingualism occurs when a child acquires two languages at the same time, and sequential bilingualism occurs when a child acquires a second language after already acquiring a native lan-guage (Carroll, 2008). The focus of this study is on simultaneous bilinguals. Extant literature has already demonstrated that both simultaneous bilinguals and monolinguals proceed through the same stages and pathways of language development and eventually arrive at the same levels of grammatical competence (Meisel, 2001). The rate of morphosyntactic devel-opment has also been shown to be equivalent across bilinguals and monolinguals (Paradis & Genesee, 1996). The issue under review in the current study is the possible interaction between the two languages a given bilingual speaks. A debate currently exists regarding how (if at all) one of a bilingual’s languag-es influences the other, and whether this influence occurs in one direction, both directions, or neither direction.

The current study seeks to investigate the existence of crosslinguistic influences in the form of language transfer, one of the manifestations of language interdependence illustrated by Paradis and Genesee (1996). Language transfer is defined as “the incorpo-ration of a grammatical property into one language from another” (1996: 3). A common example of language transfer would be the borrowing of whole words from one language for use in another (e.g. a German-Italian bilingual using certain Italian nouns in place of their German counterparts when speaking German). This study attempts to determine whether the language development of simultaneous bilinguals

differs from that of monolinguals due to interactions between the children’s two spoken languages Results on language transfer have generally been mixed, but some conclusions can be drawn. Smith (cited in McLaughlin, 1984) found that children stop produc-ing mixed-language sentences around the age of 3. Petitto et al. (2001) found little transfer in a bilin-gual sign language-spoken language sample, arguing that exposure to two languages from birth does not necessarily lead to interference or confusion between the two languages. Genesee (1989) and Reich (1986) found transfer at the levels of phonology, syntax, and the lexicon, with the most frequent transfer ef-fects between languages occurring at the lexical level in the form of word borrowing. Depending on the particular languages and linguistic structures being examined, some researchers have found evidence for crosslinguistic influence, while others have not, lead-ing some to conclude that triggers for crosslinguistic influence do not operate universally on all languages (Zwanziger, Allen & Genesee, 2006). Among those reporting no evidence for crosslinguistic influence are Paradis & Genesee (1996) who looked at English-French bilingual children and Meisel (1994) who studied French-German bilingual children. Both studies found that the bilinguals examined behaved like monolinguals. On the other hand, both Döpke (1997, 2000) and Hulk and Müller (2000) found cross-linguistic interactions in the grammars of bilingual children, apparently caused by both language-internal and language-external factors.

Hulk and Müller (2000) posited that crosslinguistic influence occurs under two conditions. First, there must be an interface between two modules of gram-mar (e.g., pragmatics and syntax). An interface has been defined as a component that links sub-modules of language (Chomsky, 1995). Second, the two lan-guages under examination must overlap in struc-ture on the surface level. That is, when one of the languages provideslanguages provides two possible analyses for a target structure (e.g.,null arguments, where the argument position is occupied by an un-pronounced pronoun, and overt arguments, where the argument position is occupied by a pronounced pronoun/ deterimner phrase) and the other language


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seems to provide support for only one of these two analyses (i.e., null arguments), crosslinguistic influ-ence from the latter to the former is likely to occur. In support of this structural overlap hypothesis, Müller and Hulk (2001) demonstrated that both a Dutch-French and a German-Italian bilingual child (between the ages of 1;8 and 3;10) omitted more objects in French and Italian than is typical for monolingual French and Italian children, due to influence from the topic-drop languages German and Dutch. The language phenomenon (object drop) studied fulfills the first condition of the hypothesis, while the lan-guage pairs studied fulfill the second condition of the hypothesis. Up to now, however, evidence in support of the Hulk and Müller (2000) hypothesis is mixed. Yip and Matthews (2007), who studied Cantonese-English bilinguals, found that the “bilingual children’s English clearly differ[ed] from that of monolinguals in that null objects are licensed in their grammar, due to crosslinguistic influence from Cantonese” (Yip & Matthews, 2007), as the bilingual children’s English featured more null objects than the speech of their monolingual counterparts. Conversely, several stud-ies have been unable to find this early crosslinguistic influence. Research by Zwanziger et al. (2006) on six English-Inuktitut bilinguals aged 1;8-3;9 found monolingual-like acquisition patterns and subject omission rates, indicating no transfer or crosslinguis-tic effects. Similarly, a study of one Japanese-English bilingual child aged 2;7-2;8 by Oshima-Takane, Genesee, Guerriero, and Hirakawa (2004) and a study of two Japanese-English bilingual children aged 3;0-3;2 by Mishina-Mori (2006) both showed no lan-guage transfer, indicating that the bilinguals acquired language-specific patterns of argument representa-tion in each language.

Serratrice, Sorace and Paoli (2004) proposed that crosslinguistic influence at the syntax-pragmatics interface might occur in two separate phases, depend-ing on the status of the C-domain, where syntax and pragmatics interact. In the earlier phase, before the domain’s instantiation, the interface effects proposed by Hulk and Müller (2000) would be found. In this stage, bilingual children would commit grammati-cal errors in one language due to the influence of the

other language. In the second stage, after the do-main’s instantiation (said to occur around the age of three), bilingual children would become more sus-ceptible to making pragmatic errors in one language without committing grammatical errors because of the confusing evidence from the pragmatics of the other language. In support of their hypothesis on the second stage of language development, Serratrice et al. (2004) found that an Italian-English bilingual child (1;10 – 4;6) showed no evidence for early crossling-uistic influence between the two languages, but later on the child produced pragmatically inappropriate pronominal subjects in contexts where a monolingual would use a null subject. Further evidence comes from a study by Haznedar (2007), who found transfer effects from English to Turkish in a Turkish-English bilingual child aged 2;4-3;10, that led to a higher proportion of overt arguments in Turkish in con-texts where subject-drop was permitted. Inconsistent with Serratrice et al.’s (2004) hypothesis, however, are studies that present similar findings much earlier in the bilingual child’s development, possibly before the C-domain has been instantiated. Paradis and Navarro (2003) reported crosslinguistic effects in a Spanish-English bilingual child aged 1;9-2;6, an age range seemingly in the “first phase” of the Serratrice et al. hypothesis.

Recently, Blais, Oshima-Takane, Genesee, and Hiraka-wa (2010) demonstrated this later stage of crosslin-guistic influence. They chose to analyze Japanese and French, two typologically distant languages, relative to the language combinations extant in the current literature. Japanese is a topic-drop language, in which null arguments can be used in either the subject or object positions grammatically. While argument omissions often occur in Japanese when the refer-ents are mentioned previously using lexical forms or understood from context, preference for lexical arguments in subject positions has also been observed even when referents are not ambiguous. In contrast, the omission of both subjects and objects is prohib-ited in French, and pronominal forms are used for previously introduced referents.

Blais et al. hypothesized that these differences in


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argument realization between the two languages would lead to bi-directional crosslinguistic transfer in pragmatically optional phenomena at the later stages of language acquisition. Consistent with their hy-potheses, 11 Japanese-French bilinguals aged 4;0-6;0 showed a relatively high proportion of pronominal arguments in Japanese, presumably due to transfer from French, and a relatively high proportion of lexi-cal arguments in French, presumably due to transfer from Japanese. Children falling in this older age range should be past the point of C-domain instantiation, and therefore prime candidates for the surfacing of any crosslinguistic effects according to the Ser-ratrice et al. hypothesis (2004). Blais et al.’s study is one of only a few studies that analyzes a combination of Japanese and an Indo-European language (e.g., English and French), as the majority of bilingual studies to date have considered evidence from two Indo-European languages (French-German: Meisel, 1994; French-English: Paradis & Genesee, 1996; Italian-French: Müller & Hulk, 2001). Their study also diverged from much previous work by analyzing 11 bilingual children, as opposed to just one or two as is often the case. Also, while most research in the field of bilingual language development analyzes spon-taneous children’s speech, their study obtained data using a controlled laboratory task.

The purpose of the present study was to replicate the findings of the Blais et al. (2010) study by deter-mining whether similar bi-directional crosslinguistic transfer effects would be observed for Japanese-English bilinguals. Like French, English is an overt argument language, which only allows the omis-sion of both subjects and objects in limited contexts (Goldberg, 2001). Thus, it was expected that the differences between argument realization in English and Japanese would make Japanese-English bilinguals vulnerable to bi-directional crosslinguistic influence at the later stages of acquisition. In order to replicate Blais et al.’s (2010) results, Japanese-English bilin-gual children aged 4;0-6;0 were studied using the same tasks and the same procedures as those used in Blais et al.’s study. Japanese-English bilingual, Japa-nese monolingual, and English monolingual children performed the Referential Communication Task,

designed to elicit utterances describing intransitive and transitive action events in order to communicate with an experimenter. Bilinguals completed the task in both languages. Following Blais et al.’s (2010) hypothesis, it was predicted that bilinguals speaking Japanese would use more pronominal forms than the Japanese monolinguals did, and use a higher propor-tion of lexical forms in English than English mono-linguals did.

MethodParticipantsThe participants were 35 children between the ages of 4 and 6 years old. There were 13 Japanese-English bilinguals (6 males), 11 Japanese monolinguals (4 males), and 11 English monolinguals (4 males). The English monolinguals were recruited from Montreal, Canada, and their testing was conducted in a uni-versity lab in the same city. The bilinguals and the Japanese monolinguals were recruited and tested in Japan. Japanese monolinguals were tested at a daycare centre near Tokyo, and bilinguals were tested at an international preschool in Osaka. Only children who completed the tasks properly were included in the present analysis. Those included were matched by age between language groups. A one-way ANOVA of the children’s ages found no significant differences in age among the three language groups (p>.05). The demographic characteristics of each language group are reported in Table 1.

Table 1Means (M) and standard deviations (SD) of age, EOWPVT vocabu-lary scores in each language, for Japanese-English bilinguals (BEJ), English monolinguals (ME), and Japanese monolinguals (MJ)


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designed to elicit utterances describing intransitive and transitive action events in order to communicate with an experimenter. Bilinguals completed the task in both languages. Following Blais et al.’s (2010) hypothesis, it was predicted that bilinguals speaking Japanese would use more pronominal forms than the Japanese monolinguals did, and use a higher propor-tion of lexical forms in English than English mono-linguals did.

MethodParticipantsThe participants were 35 children between the ages of 4 and 6 years old. There were 13 Japanese-English bilinguals (6 males), 11 Japanese monolinguals (4 males), and 11 English monolinguals (4 males). The English monolinguals were recruited from Montreal, Canada, and their testing was conducted in a uni-versity lab in the same city. The bilinguals and the Japanese monolinguals were recruited and tested in Japan. Japanese monolinguals were tested at a daycare centre near Tokyo, and bilinguals were tested at an international preschool in Osaka. Only children who completed the tasks properly were included in the present analysis. Those included were matched by age between language groups. A one-way ANOVA of the children’s ages found no significant differences in age among the three language groups (p>.05). The demographic characteristics of each language group are reported in Table 1.

Table 1Means (M) and standard deviations (SD) of age, EOWPVT vocabu-lary scores in each language, for Japanese-English bilinguals (BEJ), English monolinguals (ME), and Japanese monolinguals (MJ)

Before the commencement of the study, language questionnaires were provided to the parents of the bilingual children in order to determine the chil-dren’s relative levels of language exposure since birth, among other things (e.g. schooling information, demographics). Questionnaires revealed that English and Japanese together accounted for at least 90% of overall language exposure for 11 out of the 13 bilin-guals participating. Two parents did not return their questionnaires. Vocabulary scores were assessed by the Expressive One-Word Picture Vocabulary Test in English and in Japanese (EOWPVT; Academic Therapy Productions, Inc., 2000) and are shown in Table 1. English vocabulary scores did not differ significantly between bilinguals and English monolin-guals, t(19)=0.01, p=0.99. The difference between the scores of bilinguals and Japanese monolinguals was marginally significant, however, with monolinguals having slightly higher scores on average t(22)=1.92, p=0.06. A statistically significant result was found between the respective English and Japanese vocabu-lary scores of the bilinguals, t(12)=3.86, p=.002, with English scores being significantly higher than Japa-nese scores. This particular result corresponds with the finding that 10 of the 13 bilinguals received much greater exposure to English than Japanese, according to parental reports. Only one of the bilinguals had a higher vocabulary score for Japanese than for English, once again corresponding with the child’s language exposure levels (relative exposure to Japanese over English: 90% vs. 10%).

Tasks and ProcedureReferential Communication Task (RCT). All children completed a Referential Communication Task (RCT) before the EOWPVT was administered. The RCT consisted of eight pairs of animated pictures (Zvaig-zne, Oshima-Takane, Groleau, Nakamura & Genesee, 2008). Each set of images was presented side by side, one by one, on a Dell Inspiron 6400 laptop connected to an LCD VA503b Viewsonic monitor (30.40 x 34.75 cm). Each set of animations consisted of a pair of animals performing some activity or action. The ani-mals were identical but had one feature distinguish-ing them in each set. For example, one pair in the English set depicted a cat carrying a fat bird on one

side of the monitor, and a skinny bird on the other side of the monitor. Everything else about the images was identical. Four trials involved differences in the animals’ manner of motion (e.g., wings flapping vs. wings not flapping), and the other four trials involved differences in the animals’ physical characteristics (e.g., spiky fish vs. smooth fish). The eight animals used for the English testing differed from the ones used for the Japanese testing in order to ensure that the bilinguals (who completed the task once in each language) did not become too familiar or too bored with the task. Table 2 presents a summary of the distinctive features differentiating the eight sets of animations used.

Table 2Distinctive features of target and non-target cartoons used in the dif-ferent language sessions and the animals in each cartoon


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Three practice trials were given to the participants before the test trials were administered in order to fa-miliarize the children with the task. For the test trials, all children viewed the same distinctive features, but the background and the animals differed between lan-guage groups. In order to eliminate order effects, two orders of presentation were used. These orders were counterbalanced across participants.

During testing sessions, the child and experimenter were seated at a table across from each other, with the experimenter operating the laptop and the child fac-ing the monitor only. A Java-script program displayed each pair of animations in loops until the experiment-er changed trials by pressing a key for the next set to appear. A plain yellow star also appeared above the “target” member of each pair of cartoons. The out-put of the laptop was simultaneously displayed on the monitor facing the child.

The RCT was explained to each child as a game in which he or she would need to explain to the exper-imenter which of two animations on the screen had a yellow star above it, using either verbal or gestural clues. The experimenter would then try to “guess” which animation the child was referring to based on the clues. The children were led to believe that the ex-perimenter’s screen did not have any stars present over the animations, meaning that he or she would need to rely on the child for this information. On each trial, the child was asked to describe what distinguished the target animation from the other image (e.g., What’s different about these two pictures?). After one or more descriptions by the child, the experimenter would then press a button corresponding to which animation he or she believed the child was describing. If the child was correct, the star’s face began to smile, and if the child was incorrect, the star’s face appeared confused. Chil-dren who struggled with the task were given addition-al question prompts unrelated to the distinguishing feature in order to elicit communication and an even-tual answer. The experimenters provided only positive feedback and each child was rewarded after each trial with a sticker of his or her choice regardless of answer accuracy. The experimenters were native speakers of the language in which the session was conducted. For

the bilingual subjects, two sessions (one for each spo-ken language) were conducted between one and three weeks apart, with the order of language sessions coun-terbalanced.

Expressive One-Word Picture Vocabulary Test (EOWPVT). Expressive vocabulary was assessed using the Expres-sive One-Word Picture Vocabulary Test (EOWPVT; Academic Therapy Productions, Inc., 2000). Children were shown pictures one at a time and asked to name the item(s) depicted in them. The original English version of the test was adapted for Japanese, with 18 inappropriate items being removed from the Japanese version due to cultural differences. Furthermore, the test was administered starting at the three-year-old level (younger than the actual age of the participants) to account for any potential linguistic developmental delays present in the bilinguals. The test was modified from the original termination criterion of six consecu-tive errors to end when children made five consecutive errors, due to the unpredictable vocabulary profiles of the bilinguals which led them to name items sporadi-cally. Tests were scored by counting the number of items named correctly before the criterion for termi-nation had been met. The 18 excluded items were not counted.

Data AnalysisThe utterances produced by both the child and the ex-perimenter during the RCT sessions were transcribed according to CHAT (for English; MacWhinney, 2000) or JCHAT (for Japanese; Oshima-Takane, MacWhin-ney, Sirai, Miyata & Naka, 1998) conventions by native speakers of English and Japanese. Transcripts were checked for accuracy by additional native speakers, and discrepancies were discussed until a solution was reached. For each of the children’s verbal clauses, the predicate (i.e., verb) and its associated arguments were identified (i.e., subject and object). Each argument was then coded using the coder mode of the CLAN pro-gram (MacWhinney, 2000) as either lexical (e.g., the monkey is swinging), pronominal (e.g., he is swinging), demonstrative (e.g., this one is swinging), or null (e.g., ø is swinging - grammatical in Japanese but not Eng-lish). Any referent containing identifying information


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was considered to be lexical (e.g., the big one). For purposes of data analysis, pronouns and demonstra-tives were grouped together as “pronouns” because both are overt non-lexical argument realizations.

The proportion of each argument form used in a RCT session was calculated for each child and was used as the dependent variable.

English coding was performed by a native English-speaker, while a native speaker of Japanese coded the Japanese transcripts. A second pair of coders coded a portion of the transcripts for reliability. The mean percentage agreement was 96% (range: 92-100%) for the Japanese monolingual transcripts. Due to time constraints, there was no reliability coding performed for the remaining transcripts at the time of writing.

ResultsFigure 1 presents the mean proportions of each argu-ment form (lexical, pronominal, and null) used by each of the three language groups tested. It is impor-tant to note that the “pronominal” category includes both standard pronouns as well as demonstratives. Two-tailed independent-samples t-tests were used to compare the speech of the bilinguals and the mono-linguals. The bilinguals’ two language sessions were

compared using paired-sample t-tests. The signifi-cance level was .05 for all statistics reported in this paper.

The argument realizations of the Japanese and Eng-lish monolinguals were markedly different. Japanese monolinguals tended to use more lexical argument forms than English monolinguals, but this difference was only marginally significant (MJ: 55% vs. ME: 44%; t(20)=1.74, p=.097). English monolinguals used significantly more pronominal forms (MJ: 10% vs. ME: 53%; t(20)=7.15, p<.001) and Japanese mono-linguals used significantly more null forms (MJ: 34% vs. ME: 3%; t(20)=6.7, p<.001). The bilingual par-ticipants followed almost analogous patterns, using similar levels of lexical argument forms for both languages (BJ: 39% vs. BE: 45%; t(12)=1.04, p=.317), using significantly more pronominal forms when speaking English (BJ: 12% vs. BE: 51%; t(12)=5.03, p<.001), and using significantly more null forms when speaking Japanese (BJ: 43% vs. BE: 10%; t(12)=5.39, p<.001). The bilinguals’ results, however, were slightly different from the monolinguals’ results because there was no significant difference found for lexical forms in the bilingual language group while a marginal difference was found in the monolingual language groups. These findings are consistent with


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Figure 1: Mean proportions of null, pronominal (PRN) and lexical (LEX) argument forms by language group.ME: Monolingual English BE: Bilingual English BJ: Bilingual Japanese MJ: Monolingual Japanese

the findings of Blais et al. (2010) with respect to Japanese and French.

Inconsistent with earlier predictions and the results of Blais et al. (2010), no significant differences were found between the Japanese speech of bilinguals and Japanese monolinguals or between the Eng-lish speech of bilinguals and English monolinguals. Bilinguals speaking English did not display signifi-cantly different proportions of lexical (ME: 44% vs. BE: 39%; t(22)=.58, p=.571), pronominal (ME: 53% vs. BE: 51%; t(22)=2.47, p=.807), or null (ME: 3% vs. BE: 10%; t(22)=1.26, p=.222) argument forms from English monolinguals. Furthermore, bilinguals speaking Japanese did not display significantly dif-ferent proportions of lexical (MJ: 55% vs. BJ: 45%; t(22)=1.34, p=.194), pronominal (MJ: 10% vs. BJ: 11%; t(22)=.358, p=.724), or null (MJ: 34% vs. BJ: 43%; t(22)=1.19, p=.246) argument forms from Japa-nese monolinguals. Bilinguals therefore behaved like the monolinguals for each of their two spoken lan-guages.

DiscussionAccording to the present hypothesis, it was predicted that bi-directional crosslinguistic effects would be found in the speech of the Japanese-English bilin-guals examined, meaning that transfer effects would be found from Japanese to English and from English to Japanese. The present results disconfirmed this hypothesis, as no transfer was identified from either Japanese to English or from English to Japanese. T-tests of the relative proportions of argument realiza-tions revealed that the bilinguals speaking English and Japanese showed no significant differences from the monolinguals speaking the same languages, re-spectively. This indicates that the bilingual children developed language-specific patterns in each of their spoken languages. Thus, the present study failed to replicate the findings of Blais et al. (2010), despite the fact that all of the bilinguals examined were in a similar age range to that of the French-Japanese bilingual children in their study, and thus were in the later development stage following the instantiation of the C-domain, according to Serratrice et al.’s (2004)

hypothesis.

This finding is consistent, however, with the findings of both Oshima-Takane et al. (2004) and Mishina-Mori (2006) with respect to young children. Oshima-Takane et al. (2004) found no evidence for crossling-uistic influence in their study of a Japanese-English bilingual child aged (2;7-2;8). The child exhibited distinct English and Japanese patterns in her speech. Similarly, Mishina-Mori’s study on the use of null and overt subjects by two Japanese-English bilingual children aged (3;0-3;2) showed no crosslinguistic influence when compared with language-matched monolinguals in the bilinguals’ respective languages (Mishina-Mori, 2006). Apparently, both younger and older Japanese-English bilingual children can display such an absence of crosslinguistic influence.

The factors of language dominance and linguistic community may account for the discrepancy between the present study and Blais et al.’s findings. In the present study, the Japanese-English bilinguals were English-dominant, except for one who was Japanese-dominant, although they all lived in Japan. In Blais et al.’s study, the Japanese-French bilinguals examined lived in Montreal and only four out of the 11 bilin-guals were French-dominant. In addition, Yip and Matthews (2000) used the concept of language domi-nance to explain why transfer effects from Cantonese to English were found in their study. The bilingual child studied was Cantonese-dominant and living in Hong Kong at the time. The child showed influence in three areas where his two languages contrasted typologically and the authors argued that language dominance was the major determinant of this trans-fer effect. Yip and Matthews (2007) later conducted a longitudinal study of six Cantonese-English bilin-gual children aged 1;6-3;1 (at the onset of the study). Results revealed unidirectional transfer from Canton-ese to English, with bilinguals producing null object sentences in English at a higher rate than did their English monolingual counterparts. They also found that the resolution of ungrammatical null object sen-tences in English was delayed significantly, with some bilinguals using null objects in English as late as six years of age. The authors concluded that transfer was


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caused by two factors. First, the ambiguity of the English input allowed a Chinese-style analysis to be undertaken by the bilinguals. The second factor was language dominance. A positive correlation was found between the child’s dominance in Cantonese and an increased use of null objects in English, demonstrat-ing more language transfer from Cantonese. Argyri and Sorace (2007) examined whether the language dominance and the community language of bilinguals were both important factors underlying transfer ef-fects. They studied 32 English-Greek bilinguals, half of whom were Greek-dominant and living in Greece and half of whom were English-dominant and liv-ing in the United Kingdom. When speaking English, bilinguals behaved similarly to monolinguals. How-ever, unidirectional transfer was found from English to Greek, but only in the English-dominant bilingual group. This finding was likely the case because the Greek-dominant group’s exposure to English was not sufficient to lead to any transfer effects to Greek because this group was living in Greece. Conversely, those in the English-dominant group had both domi-nance and a higher level of input in the influencing language (i.e., English), leading the transfer effects to surface. The authors argued that sufficient input was required in order to “tip the balance” in the favour of transfer. Most recently, Foroodi-Nejad and Paradis (2009) reported the effects of language dominance and bi-directional crosslinguistic transfer in the for-mation of compounds in English-Persian bilinguals. They analyzed 16 English-Persian bilinguals in Cana-da, half of whom were English-dominant and half of whom were Persian-dominant. Bilinguals produced more right-headed compounds when speaking Per-sian and more left-headed compounds when speaking English, compared to monolinguals of the respective languages (English compounds are right-headed, Per-sian compounds are left-headed), indicating a bi-di-rectional transfer effect. Most interestingly, however, was the fact that the Persian-dominant bilinguals pro-duced more left-headed compounds in Persian than the English-dominant group speaking the same lan-guage. Thus, Persian-dominant bilinguals did in fact behave like monolinguals in their dominant language, but it was also found that English-dominant bilin-guals did not behave like English monolinguals. The

authors took this finding as partial evidence for their dominance hypothesis, that in bilinguals the dominant language should influence the non-dominant one, and that monolingual-like patterns should emerge in the bilinguals’ dominant language. The findings of these bilingualism studies together suggest that dominance and linguistic community are at least two of the fac-tors influencing both the existence and the extent of crosslinguistic influence.

These two factors can potentially bear on the present study’s results. In the current study, most bilinguals were English-dominant. If crosslinguistic transfer is due to language dominance, then the bilinguals should show transfer effects from English to Japanese but no transfer from Japanese to English because English was their dominant language. The pres-ent finding is partially consistent with the language dominance hypothesis because bilinguals showed the same patterns as English monolinguals in their dominant language, English. Also, the fact that the bilinguals were so dominant in English with mean vocabulary levels at almost identical levels to those of the monolinguals may explain why no transfer effects were found from Japanese to English. The linguistic community of the bilingual is another factor worthy of consideration and can account for the absence of transfer from English to Japanese. The Japanese-English bilinguals in the present study were living in Japan, and thus their Japanese-dominant linguis-tic environment could be a factor that shielded their Japanese from being influenced by their dominant English. Research suggests that the combination of both dominance and linguistic community in tandem may lead to transfer, but perhaps either alone is not always sufficient. For example, in the Mishina-Mori (2006) and the Zwanziger et al. (2006) studies that show no crosslinguistic transfer (for English-Japanese and English-Inuktitut bilinguals, respectively), none of the bilingual children examined were raised in the community in which the null argument language was dominantly used (i.e., the former were raised in the United States, an English-dominant community, and the latter were raised in a community in which both Inuktitut and English were used). The fact that the linguistic community provided little input in the null


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transfer was not found from the null argument language (i.e., Japanese and Inuktitut) to the overt argument language (i.e., English) as expected. Simi-larly, the factor of community language may account for the divergent findings of the present study of Japanese-English bilingual children and the Blais et al. (2010) study of Japanese-French bilinguals. While this study was mainly conducted in Japan (a Japanese linguistic environment), the Blais et al. (2010) study was conducted in Montreal (a French linguistic en-vironment). A French-dominant environment would likely lead to transfer effects from French to Japanese due to limited levels of Japanese input available to the children. For instance, three Japanese-French bilin-gual children in Blais et al.’s study used the Japanese equivalent of the English “one” (e.g., one is rolling, and one is sliding) or the French “un” (e.g., il y en a un qui roule et un qui glisse), “ikko” (e.g., ikko ga korogattete ikko ga subetteru), which is never used by monolingual Japanese speakers in this context. While no Japanese monolingual and Japanese-English bilin-gual children living in Japan (from the current study) used this expression, three bilingual Japanese-French children living in Montreal did in Blais et al.’s study. It appears that the different linguistic environments of the bilinguals in the present study and the bilin-guals in the Blais et al. (2010) study had an impact on the presence or absence of crosslinguistic influence.

The strong Japanese environment present in this study did have some minor effects on the bilinguals’ speech, albeit not any significant ones. For example, while all Japanese-French bilinguals used demonstra-tives and pronouns in their argument representations in Japanese, five out of the 13 Japanese-English bi-linguals did not use them at all when speaking Japa-nese, opting for null arguments instead (a Japanese language preference). The environmental difference between the two studies may once again account for this speech pattern.

In summary, the bi-directional effects identified by Blais et al. (2010) were not successfully extended to Japanese-English bilingual children. This study’s main finding has several main implications. First, it demonstrates that crosslinguistic influence at the

syntax-pragmatics interface may not be a language universal phenomenon. It may occur only with par-ticular structures and particular language combina-tions. Next, this study adds to the current body of literature testing the Serratrice et al. (2004) hypoth-esis on language transfer, which is the proposal that once a bilingual child’s C-system has been stabilized, crosslinguistic influence will occur at the vulner-able syntax-pragmatics interface. A strength of the present study is its contribution of a relatively large sample of bilingual children to the growing body of research on simultaneous bilingualism. The results of this study illustrate that the answer to the ques-tion of crosslinguistic influence is more complex than originally presumed. Multiple factors are at play, and will all need to be taken into account in order to predict and account for the existence of crosslinguis-tic influence. Two potential factors worthy of con-sideration are the language dominance status and the community language of the bilingual.

Future research in this area would benefit from the addition of studies analyzing new language combi-nations, with a focus on pairs of languages that are typologically distant. As well, this study could benefit from an examination of certain pragmatic features of the referents, such as their information status (i.e., given vs. new), considering the heavy emphasis the Japanese language places on such factors. The preferred argument form differs across English and Japanese when a speaker is referring to informa-tion that is given. English allows either pronouns or lexical forms to be used and Japanese allows the use of pronouns or null forms (null being the preferred form). Because the two languages under consideration do not differ strongly with respect to new informa-tion and act quite differently with respect to given information, perhaps significant differences would surface if given and new information were separated and analyzed independently. Future studies may also wish to distinguish between objects and subjects in analyses as was done by Blais et al. (2010), who found significant effects for subjects as opposed to objects. Finally, as a range of factors are involved in the oc-currence of crosslinguistic influence, experimenters using more stringent controls would be better able to


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to determine the role of each factor and its relative importance in the language transfer phenomenon. Such a study would involve bilingual controls with different dominant languages and dominance levels and the recruitment of bilinguals from more than one

linguistic community.

ReferencesAcademic Therapy Publications Inc. (2000). EOWPVT (2000 ed.) Novato: Academic Therapy Publications. Argyri, E., & Sorace, A. (2007). Crosslinguistic influence and language dominance in older bilingual children. Bilin gualism: Language and Cognition, 10(01), 79-99. Blais, M.J., Oshima-Takane, Y., Genesee, F., Hirakawa, M. (2010). Crosslinguistic influence on argument realiza tion in Japanese-French bilingual children. BUCLD 34 Proceedings (pp. 34-45). Somerville, MA: Cascadilla Press. Blais, M.J., Oshima-Takane, Y., Genesee, F., Hirakawa, M. (2010). Crosslinguistic influence on argument realiza tion in Japanese-French bilingual children. BUCLD 34 Proceedings (pp. 34-45). Somerville, MA: Cascadilla Press. Carroll, D. W. (2008). Psychology of language. Australia: Thomson/Wadsworth. Chomsky, N. (1995). The minimalist program. Cambridge, MA: The MIT Press. Döpke, S. (1997). Is the simultaneous acquisition of two lan guages in early childhood equal to acquiring each of the two languages individually? In E. Clark (Ed.), The Proceedings of the 28th Annual Child Language Research Forum (pp. 95-112). Cambridge: Cambridge University Press. Döpke, S. (2000). The interplay between language-specific devel opment and crosslinguistic influence. In S. Döpke (Ed.), Cross-Linguistic Structures in Simultaneous Bilingual ism (pp. 79-103). Amsterdam: John Benjamins Foroodi-Nejad, F., & Paradis, J. (2009). Crosslinguistic transfer in the acquisition of compound words in Persian–Eng lish bilinguals. Bilingualism: Language and Cognition, 12(04), 411-427. Genesee, F. (1989). Early bilingual development: One language or two? Journal of Child Language, 16, 161-179. Goldberg, A. (2001). Patient arguments of transitive verbs can be omitted: The role of information structure in argu ment distribution. Language Sciences, 23, 503-524. Haznedar, B. (2007). Crosslinguistic influence in Turkish- English bilingual first language acquisition: the overuse of subjects in Turkish. Proceedings of the 2nd Conference on Generative Approaches to Language Acquisition, 124-134. Somerville, MA: Cascadilla Pro ceedings Project.

Hulk, A., & Müller, N. (2000). Bilingual first language acquisi tion at the interface between syntax and pragmatics. Bilingualism: Language and Cognition, 3, 227-244. MacWhinney, B. (2000). The CHILDES project: Tools for ana lyzing talk: Vol. 1. The format and programs (3rd ed.). Mahwah, NJ: Lawrence Erlbaum Associates. Matsuoka, K., Mishina-Mori, S., & Sugioka, Y. (2008). Dis course-pragmatics analysis of subjects in Japanese/English bilingual children’s speech. Paper presented at the Conference on Bilingual Acquisition in Early Childhood, Hong Kong.

McLaughlin, B. (1984). Second language acquisition in child hood: Vol. 1. Preschool children (2nd ed.). Hillsdale, NJ: Erlbaum. Meisel, J. M. (1994). Bilingual first language acquisition: French and German grammatical development. Amsterdam: John Benjamins. Meisel, J. M. (2001). The simultaneous acquisition of two first languages: Early differentiation and subsequent devel opment of grammars. In J. Cenoz & F. Genesee (Eds.), Trends in Bilingual Acquisition (pp. 11-41). Amsterdam and Philadelphia, PA: John Benjamins. Mishina-Mori, S. (2006). Argument representation in Japanese/ English simultaneous bilinguals: Is there a crosslinguistic influence? In J. Caunt-Nulton, S. Kulatilake, & I.- H. Woo (Eds.), BUCLD 31 Proceedings (pp. 26-45). Somerville, MA: Cascadilla Press. Müller, N., & Hulk, A. (2001). Crosslinguistic influence in bilingual language acquisition: Italian and French as re cipient languages. Bilingualism: Language and Cogni tion, 4(01). Oshima-Takane, Y., MacWhinney, B., Sirai, H., Miyata, S., & Naka, N. (1998). (Eds.). Nihongo no tame no CHILDES manyuaru [CHILDES manual for Japanese] (2nd ed.). Nagoya, Japan: JCHAT Project.

Oshima-Takane, Y., Genesee, F., Guerriero, S., Hirakawa, M. (2004). Argument realization and omission in English -Japanese bilingual acquisition. Poster presented at the 9th Annual Boston University Conference on Language Development, Boston. Paradis, J., & Genesee, F. (1996). Syntactic Acquisition in Bilin gual Children. Studies in Second Language Acquisition, 18(01), 1-15. Paradis, J., & Navarro, S. (2003). Subject realization and crosslin guistic interference in the bilingual acquisition of Span ish and English. Journal of Child Language, 30, 371- 393.Petitto, L. A., Katerelos, M., Levy, B. G., Gauna, K., Tetrault,K., & Ferraro, V. (2001). Bilingual signed and spoken language acquisition from birth: Implications for the mechanisms underlying bilingual language acquisition. Journal of Child Language, 28, 453-496.


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Reich, P.A. (1986). Language Development. Englewood Cliffs, NJ: Prentice Hall. Serratrice, L., Sorace, A., & Paoli, S. (1999). Crossling uistic influence at the syntax–pragmatics interface: Subjects and objects in English–Italian bilingual and monolingual acquisition. Bilingualism: Language and Cognition, 7(3), 183-205.

Yip, V., & Matthews, S. (2000). Syntactic transfer in a Cantonese- English bilingual child. Bilingualism: Language and Cognition, 3, 193-208. Yip, V., & Matthews, S. (2007). The bilingual child: early devel opment and language contact. Cambridge: Cambridge University Press. Zvaignze, M., Oshima-Takane, Y., Groleau, P., Nakamura, K. & Genesee, F. (2008). The function of children’s iconic co-speech gestures: A study with French-Japanese bilinguals and French Monolinguals. In H. Chan, H. Jacob, & E. Kapia (Eds.), BUCLD 32 Proceedings (pp. 598-597). Somerville, MA: Cascadilla Press. Zwanziger, E. E., Allen, S. M., & Genesee, F. (2005). Crosslin- guistic influence in bilingual acquisition: subject omis sion in learners of Inuktitut and English. Journal of Child Language, 32(04), 893-909.


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Empirical Evidence for a Relationship Between Exercise and

Decreases in Depression and Anxiety

Zoë Prowse

AbstractPhysical activity is a desirable behaviour associated with many health benefits and its absence can have harm-ful effects on health and well-being, as is has been shown to increase the risk for obesity, heart disease, diabetes, hypertension, and certain cancers. Lack of physical activity has also been linked with a decline in mental health, as some studies have shown associations between reduced physical activity and symptoms of depression and anxi-ety. Current treatments for depression and anxiety raise questions of clinical effectiveness, often have unpleasant side effects, and are expensive. Thus, the implications of research looking at the impact of exercise on depres-sion and anxiety could be a great alternative to anti-depressants since exercise is inexpensive and essentially free from side-effects. There is abundant literature on the topic of exercise and its effects on alleviating depression and anxiety, however upon close examination many of the studies are methodologically flawed, the underlying mecha-nisms remain unknown, and the evidence for implementation is questionable. Future studies should inquire into the mechanisms underlying a decrease in depression and anxiety as a result of exercise, and more longitudinal and international studies should be done.

IntroductionPhysical activity is a desirable behaviour associated with many health benefits and its absence can have harmful effects on health and well-being, as is has been shown to increase the risk for obesity, heart disease, diabetes, hypertension, and certain cancers (CDC, 1999; CSEP, 2003). Lack of physical activity has also been linked with a decline in mental health, as some studies have shown associations between re-duced physical activity and symptoms of depression and anxiety (Ruuskanen & Ruoppila, 1995; Lampinen et al., 2000). Anxiety disorders affect around 18% of Americans (NIMH, 2008) and 12% of Canadians (ADAC, 2003), and are often comorbid with depres-sion, which is the leading cause of disability in ages

15-44 and affects around 7% of Americans (NIMH, 2008) and 14% of Canadians (CMHA, 2001). Clearly, lack of exercise is a serious health problem asso-ciated with many negative consequences on both physical and mental health. This paper will discuss the empirical evidence for a relationship between exercise and decreases in depression and anxiety.

BackgroundMany countries have altered their recommenda-tions for physical activity recently in response to the growing excitement about the effects of exercise in scholarly journals and research projects. The Public Health Agency of Canada published a handbook

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that recommends that Canadians engage in endur-ance and flexibility activities 4-7 days per week, as well as strength activities 2-4 days per week, for a total of 30-60 minutes minimum per day depending on intensity to maintain health (CSEP, 2003). Cross-nationally, physical activity can now be measured using the International Physical Activity Question-naire (IPAQ), which has been found to be a valid and reliable measure of physical activity and inactivity in people aged 18-65 years of age (Craig et al., 2003; Hagtsrömer, 2006). There are a number of different theories that aim to explain the possible mechanisms underlying decreases in depression and anxiety due to an increase in exercise and physical activity, which will be outlined hereinafter. Physiological models postulate that exercise acts like an antidepressant medication, increasing monoaminergic transmission of dopamine (DA), noradrenaline (NE), and serotonin (5-HT) in the central nervous system (Chaouloff, 1989; Ransford, 1982) which results in an increase of endogenous opioids and thus a rise in mood (Knech-tle, 2004), and that it reduces physiological reactions to stressors (Taylor et al., 1985). Cognitive models suggest that exercising improves self-image, increases perceived ability to cope with stress, and gives a sense of mastery and control to the depressed or anxious person, and that all these positive effects carry over into other aspects of life (Mellion, 1985, Taylor et al., 1985, Steptoe et al., 1989).

Exercise and Decreases in Depression and Anxiety

DepressionThere have been many studies published that sug-gest physical activity and exercise may reduce symp-toms of depression (Ransford, 1982; Chaouloff, 1989; Knechtle, 2004; Taylor et al., 1985; Mellion, 1985), and cross-sectional studies have consistently correlat-ed self-reported regular exercise with lower depres-sion rates in all age groups (Ruuskanen & Ruopilla, 1992; CSEP, 2003, Blumenthal et al., 1999). However, much of the early literature on the effects of exercise on decreases in depression is methodologically flawed

(for example, the very first study that claimed to find proof on the topic, by McCann and Holmes (1984), had a small sample drawn only from one introduc-tory Psychology class at one school). Furthermore, cross-sectional studies alone cannot necessarily infer causation; therefore meta-analytical and longitudinal studies must be examined.

Meta-analyses provide a way to review the entire body of literature and identify variables that may play a role in affecting the effects of exercise on depres-sion. North et al. (1990), performed a meta-analysis of 80 studies and reported a large effect size (ES) of -0.53 in depressed subjects, meaning that physical activity and exercise definitively reduced depression scores. Craft and Landers (1998) found an even higher effect size of -0.72 in patients diagnosed with Major Depressive Disorder (MDD). They also found that the only moderator of clinical effects was the length of the exercise program; the program must exceed 9 weeks in order to experience larger reductions in depressive symptoms to be seen. Stathopoulou et al. (2006) reported the highest effect size of -1.42 for the effects of exercise and physical activity on the reduc-tion on depression compared to controls. These find-ings are consistent with the notion that increases in exercise and physical activity are related to a decrease in depression.

Dunn et al. (2005) conducted a randomized and con-trolled longitudinal study between 1998 and 2001 to investigate whether exercise is a useful treat-ment for mild to moderate MDD and to test the dose-response relation of exercise and reduction in depres-sive symptoms. Subjects were randomly assigned to one of four aerobic exercise treatment groups (vary-ing in intensity and frequency), or to the exercise placebo group (flexibility exercises). Subjects were tested at baseline and 12 weeks later. They found that the Hamilton Rating Scale for Depression (HAM-D) scores at week 12 were reduced 47% from baseline compared to 29% in the control group. It is also im-portant to note that this 47% reduction occurred in the aerobic group whose intensity and frequency was consistent with public health recommendations, and that another less intense aerobic group saw effects


40

comparable to the placebo group, at 30% reductionfrom baseline (Dunn et al., 2005).

Blumenthal et al.’s (1999) 16-week randomized, con-trolled trial of MDD patients aged 50 years and older found an aerobic exercise program to be as effective as antidepressant medication (sertraline hydrochlo-ride). Subjects were assigned to either an aerobic exercise group, an antidepressant medication group, or an exercise and medication group, and received comprehensive evaluations of depression including the DSM-IV, the HAM-D, and the Beck Depression Inventory (BDI) before and after treatment. The three groups did not differ statistically on HAM-D or BDI scores, and growth curve models illustrated that all groups had statistically significant reductions on HAM-D and BDI scores. The only difference was that the medication group showed the fastest initial response. More recently, Blumenthal et al. (2007) performed a similar study using another randomized, controlled longitudinal study between 2000 and 2005 on 202 patients diagnosed with MDD. Subjects were assessed with the HAM-D and randomly assigned to one of four conditions: supervised group exer-cise, home-based exercise, antidepressant medication (sertraline), or placebo pill. They found that after 4 months of treatment, 41% of participants achieved remission, as defined by HAM-D scores of <8 and no longer meeting the DSM-IV criteria for MDD. All treatment groups had higher remission rates than the placebo group, and Blumenthal et al. (2007) con-cluded that exercise programs seem to be generally comparable with antidepressant medication, and both tend to be better than the placebo in treating patients with MDD.

AnxietyAs outlined previously, there has been a great deal of attention surrounding research on the effects of exercise on depression, but there are far fewer studies on the effects of exercise on anxiety.Early studies have found anxiolytic effects, but they have been done mainly on healthy subjects and not on clinical subjects (Long & Stavel, 1995). In one study unlike any of its methodologically questionable predecessors (i.e.: Martinsen, Hoffart, and Solberg,

1989, who drew their sample from hospital inpa-tients and had no control group), Steptoe et al. (1989) collected a representative sample of anxious adults 20-60 years of age who responded to a newspaper ad and reported low levels of physical activity, and confirmed clinical anxiety using the Hospital Anxiety and Depression Scale as well as the Profile of Moods States scale. Subjects were matched for age, gender, body weight, and initial anxiety level, then divided into either a moderate aerobic training condition or a strength and flexibility placebo group. They found that the moderate exercise program resulted in great-er reductions in anxiety, depression, and negative affect than were found in the placebo condition, as well as increased ability to cope with stress. Follow-up tests revealed that these positive effects were still maintained three months later (Steptoe et al., 1989).

Petruzello et al. (1991) conducted three meta-analyses to analyze the literature on the effects of exercise on three qualities of anxiety: state anxiety (acute), trait anxiety (chronic), and the psychophysiological correlates of anxiety. Exercise was associated with reduced state anxiety and trait anxiety, and was found to act in a similar way as previously known forms of anxiety- reducing treat-ments, such as relaxation and meditation. Further, they found that exercise programs needed to continue for more than 10 weeks in order for significant chang-es in trait anxiety to occur, and exercise must last at least 21 minutes in order to see reductions in both state and trait anxiety (Petruzello et al., 1991).

In an interesting longitudinal study, Oeland et al. (2010) performed a controlled, non-blinded ex-periment on patients referred by private psychiatric practices and private general practices. Their research goal was to investigate if psychiatric patients with depressive and/or anxiety disorders could increase their fitness level to meet public health recommenda-tions, and in doing so increase their quality of life through nothing more than participation in an exer-cise program. Subjects were randomly divided into either an intervention group or a control group. The intervention group underwent 20 weeks of exercise as a group, including both aerobic and non-aerobic


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training (weight lifting). Both groups were tested and interviewed at baseline, at week 20, and at week 32.The interesting part is what they were looking for: not direct symptoms of depression and/or anxiety in particular, but improvement in fitness level and qual-ity of life. Quality of life is consistently rated lower than average in populations of depressed and anxious people (Galper, 2006), as are levels of exercise. With these low rating comes all the negative consequences of lack of exercise as previously outlined. So, increas-ing fitness and quality of life results in an ameliora-tion or elimination of depressive symptoms in this very recent study.

Summary and Critique

Current treatments for depression and anxiety raise questions of clinical effectiveness, often have unpleas-ant side effects, and are expensive. Thus, the implica-tions of research looking at the impact of exercise on depression and anxiety could be a great alternative to anti-depressants since exercise is inexpensive and essentially free from side-effects. As this paper has outlined, there is much empirical evidence demon-strating a relationship between exercise and decreases in depression and anxiety, especially depression. However, many of the studies are methodologically flawed due to small, unrepresentative samples (Mc-Cann & Holmes, 1984), too many different variables for depression and anxiety, or lack of a control group (Martinsen, Hoffart, & Solberg, 1989). Further, the mechanisms underlying a reduction in depression and anxiety as a result of exercise and physical activity are not yet clear, and the limited number of studies that investigate this are not reliable. Blumenthal et al.’s studies (1999, 2007) are very promising support for exercise as an alternative treatment for depression and anxiety, but they are limited by the fact that only one type of antidepressant medication was used (ser-traline). There is abundant literature on the topic of exercise and its effects on alleviating depression and anxiety, however upon close examination many of the studies are methodologically flawed, the underlying mechanisms remain unknown, and the evidence for implementation is questionable. Future studies should inquire into the mechanisms underlying a decrease

in depression and anxiety as a result of exercise, and more longitudinal and international studies should be done, drawing from Blumenthal et al.’s example and using the IPAQ to make cross-national comparisons.

ReferencesADAC (2003). Treatment guidelines for Social Anxiety Disor der.Anxiety Disorders Association of Canada Blumenthal, J.A., Babyak, M.A., Moore, K.A., Craighead, W.E., Herman, S., Khatri, P., ... Krishnan, K.R. (1999) Effects of exercise training on older patients with major de pression. Archives of Internal Medicine 159 (19): 2349- 2356. Blumenthal, J.A., Babyak, M.A., Doraiswamy, P.M., Watkins, L., Hoffman ,B.M., Barbour, K.A., ...Sherwood, A. (2007) Exercise and pharmacotherapy in the treatment of major depressive disorder. Psychosomatic Medicine. 69(7):587-96 CSEP: Canadian Society for Exercise Physiology (2003) Canada’s physical activity guide. Public Health Agency of Canada. CDC (1999). Physical activity and health: a report of the Sur- geon General. Centres for Disease Control and Prevention, US Department of Health and Human Services. Chaouloff, F. (1989) Physical exercise and brain monoamines: a review. Acta Physiologica Scandinavica.137(1):1-13 CMHA (2001) The 2001 Canadian mental health survey. Cana- dian Mental Health Association. Craft, L.L., Landers, D.M. (1998) The effects of exercise on clinical depression resulting from mental illness: a meta-analysis. Journal of Sports and Exercise Psychology. 20:339-357 Craig, C.L., Marshall, A.L., Sjöström, M., Bauman, A.E., Booth, M.L., Ainsworth, B.E., ... Oja, P. (2003) International Physical Activity Questionnaire: 12-country reliability and validity. Medicine and Science in Sports and Exercise 35(8):1381-1395 Galper, D.I., Trivedi, M.H., Barlow, C.E., Dunn, A.L., Kampert, J.B. (2006) Inverse association between physical inactiv ity and mental health in men and women. Medical Sci ence in Sports and Exercise. 38:173-8. Hagströmer, M., Oja, P., Sjöström, M. (2006)The International Physical Activity Questionnaire (IPAQ): a study of con current and construct validity. Public Health Nutrition. 9(6):755-62 Lampinen, P., Heikkinen, R.L., Ruoppila, I. (2000) Changes in intensity of physical exercise as predictors of depressive symptoms among older adults: an eight-year follow-up. Preventative Medicine 30(5):371-80


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Long, B.C., van Stavel, R. (1995) Effects of exercise training on anxiety: a meta-analysis. Journal of Applied Sports Psychology 7:167-189 Martinsen, E.W., Hoffart, A., Solberg, O. (1989) Comparing aerobic with nonaerobic forms of exercise in the treatment of clinical depression: a randomized trial. Comprehensive Psychiatry. 30(4):324-31 McCann, I. L., Holmes, S. (1984). Influence of aerobic exercise on depression. Journal of Personality and Social Psy chology, 46(5): 1142-1147 Mellion, M.B. (1985) Exercise therapy for anxiety and depression. 1. Does the evidence justify its recommendation? Postgraduate Medicine. 77(3):59-62, 66 NIMH (2008) The numbers count: mental disorders in America. US National Institutes of Health Oeland, A.-M., Laesso, U., Olesen, A.V., Munk-Jorgensen, P. (2010) Impact of exercise on patients with depression and anxiety. Nordic Journal of Psychiatry Petruzzello, S.J., Landers, D.M., Hatfield, B.D., Kubitz, K.A., Salazar, W. (1991) A meta-analysis on the anxiety-reducing effects of acute and chronic exercise. Outcomes and mechanisms. Sports Medicine. 11(3):143-82 Ransford, C.P. (1982) A role for amines in the antidepressant effect of exercise: a review. Medicine and Science in Sports and Exercise. 14(1):1-10 Ruuskanen, J.M., Ruoppila, I. (1995) Physical activity and psychological well-being among people aged 65 to 84 years. Age & Ageing 24(4):292-6 Stathopoulou, G., Powers, M.B., Berry, A.C., Smits, J.A.J., Otto, M.W. (2006) Exercise interventions for mental health: a quantitative and qualitative review. Clinical Psychol ogy Scientific Practice 13:179-193 Steptoe, A., Edwards, S., Moses, J., Mathews, A. (1989) The ef fects of exercise training on mood and perceived coping ability in anxious adults from the general popu lation. Journal of Psychosomatic Research. 33(5):537- 47 Ströhle, A. (2009)Physical activity, exercise, depression and anxiety disorders. Journal of Neural Transmission. 116:777-784 Taylor, C.B., Sallis, J.F., Needle, R. (1985) The relation of physi cal activity and exercise to mental health. Public Health Reports (Washington, D.C. : 1974) 100(2):195-202


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44

The Role of Mass Media Influences on Women’s Body Image and Their

Mental/Behavioural States

Bryan Lin

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The perception of female beauty in Western culture has been evolving over the past few decades (Stice, Schupak-Neuberg, Shaw, & Stein, 1994). What began in the 1960’s as a simple educational campaign on the health risks of being overweight has led to a cur-rent ideal of thinness that is most commonly por-trayed through mass media outlets, from magazine advertising to Hollywood blockbuster films (Owen & Laurel-Seller, 2000). Large-scale consequences have been felt, and a billion-dollar beauty industry has emerged that has only continued to grow, and a seemingly increasing number of women are indulg-ing in poor eating habits (Spettigue & Henderson, 2004). As a result, the influence of media on wom-en’s perception of body image and its relationship to their behavioural and mental states continues to be one of the most documented topics with regard to women’s health.

Research has investigated whether exposure to me-dia images of thin, idealized women leads to body image dissatisfaction and maladaptive eating habits amongst young women. Conclusions drawn from those studies indicate that there appears to be higher levels of self-objectification, negative internalized body image perception, and negative mood states leading to the development of eating disorder symp-toms amongst the women studied after exposure to media containing images perceived to be attractive

by other females (Harper & Tiggemann, 2008; Stice et al., 1994; Tiggeman & Pickering, 1996). However, there are also numerous studies that suggest that not all young women are equally swayed by these media images. The purpose of this review aims to outline the context specific factors and predispositions as-sociated with women who engage in highly maladap-tive body image thoughts and are vulnerable to seek-ing risky behaviours due to media-imposed standards of female beauty. This article will also highlight the opinions and experiences of three educated, female university students with regards to the impact of mass media on their personal body image perception and eating habits.

Fredrickson and Roberts (1997) define self-objec-tification as the tendency to value appearance over ability as well as any other attributes. It is a stable personality trait characterized by a person’s ability to internalize what others think of physique (Harper & Tiggemann, 2008). Harper and Tiggemann (2008) also propose that self-objectification an emotional state that will differ from one person to another depending on the amount of exposure to situations wherein they are aware of others’ judgements of their bodies. B. Sanders (personal communication, November 28, 2010) stated that a clear distinction must be made in how a woman values her physique. She noted that some women focus on body objecti-

Fredrickson and Roberts (1997) define self-objec-tification as the tendency to value appearance over ability as well as any other attributes. It is a stable personality trait characterized by a person’s ability to internalize what others think of physique (Harper & Tiggemann, 2008). Harper and Tiggemann (2008) also propose that self-objectification an emotional state that will differ from one person to another depending on the amount of exposure to situations wherein they are aware of others’ judgements of their bodies. B. Sanders (personal communication, November 28, 2010) stated that a clear distinction must be made in how a woman values her physique. She noted that some women focus on body objecti-fication and appearance while others place a greater emphasis on body functionality in terms of fitness levels and general health.

From a self-report questionnaire study of under-graduate women assessing body shame, self-objectifi-cation, dietary restraint, and disordered eating symp-toms, Noll and Fredrickson (1998) suggested that self-objectification produces body dissatisfaction and leads to eating problems.

A number of studies have shown that viewing media images of thin idealized female bodies leads to self-objectification in women. Harper and Tiggemann (2008) used a between-subjects experimental design to test 90 Australian undergraduate women between the ages of 18 and 35. Magazine advertisements featuring a thin woman, a thin woman with at least one attractive man, or no people at all were randomly distributed amongst the participants for viewing (Harper & Tiggemann, 2008).

Harper and Tiggemann (2008) concluded that only those women who viewed advertising campaigns con-taining images of thin women possessed higher levels of self-objectification and weight-related appearance anxiety in addition to declines in mood and body satisfaction. Having a man in those idealized images had little to no effect on increasing self-objectification measures (Harper & Tiggemann, 2008). A similar study conducted by Monro and Huon (2005) involved 39 female university students viewing advertising for

both body and non-body related products. The par-ticipants were shown either idealized or non-idealized images. The researchers found that product type was not a factor contributing to appearance anxiety, self-objectification, and body dissatisfaction increases. The presence of idealized thin bodies made a significant difference in both studies.

The pursuit of the thinness ideal for women does not seem to depend on the amount of exposure to dif-ferent media images but rather on the category of images being viewed (Spettigue & Henderson, 2004). Tiggemann and Pickering (1996) conducted an analy-sis of 94 adolescent girls who reported how much and what television programs they had watched in the week prior to the study. The questionnaire includ-ed a Drive for Thinness scale which assesses whether one has the attitudes and behaviours of a person who possesses an eating disorder (Tiggemann & Pickering, 1996). The Drive for Thinness scale is the primary predictor for the onset of anorexia nervosa (Tiggemann & Pickering, 1996). Results from this study indicated that those who watched soap operas and movies reported higher levels of body dissatisfac-tion (Tiggemann & Pickering, 1996) whereas women who consumed music videos were more likely to have a greater drive for thinness (Tiggemann & Picker-ing, 1996). Further research should take into ac-count the relatable nature of the media images being viewed. It can be concluded that certain categories of media have a greater influence on increasing pursu-ing actions for thinness than other categories, but it remains to be seen whether those behaviours actually include disordered eating habits.

Bissell and Zhou (2004) suggest that this discrepancy between striving for thinness and internal shame of one’s body can be attributed to the amount of thin-ideal content in different types of media. Their sur-vey report study investigated exposure to sports and entertainment media during 40 prime-time television programs and concluded that programs which con-tained more thin body images predicted disordered eating. It is unclear whether sports media plays a role in precipitating abnormal eating due to participation factors and the type of sport viewed amongst other


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factors (Bissell & Zhou, 2004).

In a cross-cultural study examining women in Lon-don and Lahore, Mumford and Choudry (2002) con-clude eating disorders are more common in societies wherein the idealized female body shape is that of slender and tubular rather than voluptuous and cur-vaceous as it is in Western society. Therefore, one of the key ingredients in making the ideal of thinness known is through the usage of mass media due to its defining influence on culture (Tiggemann & Picker-ing, 1996). However, Owen and Laurel-Seller (2000) argue against previous research on the upward trend of idealizing the tubular body shape by referring to Playboy centerfolds and internet print models pos-sessing consistently curvaceous body measurements on thinner bodies. B. Sanders (personal communica-tion, November 28, 2010) believes that the current ideal is actually a combination of two opposing trains of thought, whereby women are expected to be thin-ner then they have ever been in history and yet at the same time they are expected to have curves in the certain areas such as the breasts and the buttocks. The classic self-report questionnaire study conducted by Stice et al. demonstrated a direct relationship between media exposure to thinness ideals and de-velopment of maladaptive eating behaviours such as crash dieting and fasting. It was also discovered that gender-role stereotype exposure, internalization of thinness ideals, and body dissatisfaction significantly facilitated this relationship (Stice et al.). For example, the stereotypical gender role endorsement in media significantly contributed to indirectly increasing body dissatisfaction through elevating internalization of the thinness model (Stice et al.). This increase in body shame and autonomic internalization then directly impacts eating habits (Stice et al.). A unique study conducted by Becker, Burwell, Herzog, Hamburg, and Gilman (2002) revealed that Fijian adolescent girls with previously minimal exposure to Western me-dia showed a significant increase in abnormal eating behaviours and attitudes reminiscent of eating disor-der symptoms following the introduction of Western ideals to their lives . This may be perhaps one of the most striking examples in support of Mumford and Choudry’s (2000) analysis.

The vast amount of research implicates that the so-ciocultural pressure to be thin brought about by mass media’s influential images is the primary cause for the developing disordered eating in women. How-ever, Mills, Polivy, Herman, and Tiggemann (2002) conclude that most women who are exposed to these images do not develop disordered eating. Various studies have argued that women with a high self-ob-jectifying personality and a tendency to make upward social comparisons by internalizing thinness ideal media images without being aware of all information on the matter are at greater risk of body dissatisfac-tion and consequential actions, such as crash dieting and starvation. (Munro & Huon, 2005; Yamamiya, Cash, Melnyk, Posavac, & Posavac, 2005). In addition, overexposure to current body shape ideals can lead to an awareness plateau and subsequently dampen the negative effects on body image (Holmstrom, 2004). Furthermore, not all women strive for the thin ideal for the same reasons (Mills et al.).

In a meta-analysis of thirty-four studies examining the effects of media on young women’s body image, Holmstrom (2004) determined that attractive thin images did not have a significant effect on a woman’s body image perception. Holmstrom (2004) attributed this result to women growing so acclimated to those thin-ideal media images that they no longer indicate a difference in body satisfaction ratings. Perhaps a prospective longitudinal study would be useful to examine the possible correlation between the impact of evolving media image-depicted beauty norms at certain periods of time and the dosage accumulation of image viewings.

Yamamiya et al. define high-internalization women as those who are likely to upwardly compare their ap-pearances to high-reach targets such as those promi-nently seen in media . These women feel negatively when they fail to meet these standards. Their study of female college students found that exposure to thin ideal images negatively influenced body image perception only for those women with high-internal-ization of media ideal trends (Yamamiya et al.). This study explains why high self-objectifying women are


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also more adversely impacted by exposure than low self-objectifiers (Munro & Huon, 2005). However, the negative effects on body satisfaction substantially decrease when those high-internalization women are exposed to more media information to stimulate criti-cally thought out arguments opposing the media thin ideals (Yamamiya et al.), resulting in a decrease in both internalization and self-objectification. In turn, there will be a decline in media influence on self-de-structive behaviours to meet body ideals.

It is clear that not all women experience the negativ-ity associated with viewing thin ideal images (Mills et al.). In fact, it has been suggested that those im-ages can affect positive change by pursuit of the current attractiveness model to gain rewards instead of engaging in behaviours to escape body shame (Mills et al.). Women can have rewarding, pleasur-able experiences if their thoughts revolve around the pleasantries, success, and perks that seem to come with looking like those women exemplifying the thin ideal (Mills et al.). The reward motivated pursuit of thinness is different from the negative, shame-driven pursuit. (Mills et al.). Results are inconclusive as to whether those thinness-oriented activities include maladaptive health behaviour habits (Mills et al.). In summary, research is conclusive in suggesting that, only under very specific conditions, does media trans-mitted images of the stereotypical Western gender attractiveness ideal lead to higher levels of self-objec-tification and internalization amongst young women. The increased level of objectification is closely as-sociated with increased weight-watching anxiety and negative affect about personal body image. More often than not, however, the vast majority of women are not vulnerable to develop eating disorders as a causal result of media influences on self-objectification due differences in context, values, culture, and personality.

Current Western sociocultural attractiveness norms are unrealistic and unattainable for women because they includes both thin and curvaceous ideals. Mal-adaptive eating disorder symptoms may have a great-er probability of manifesting themselves in young women as a direct result of exposure to certain categories of media which contain more thin-ideal fe-

male images that are relatable to the individual. Cer-tain women who value external appearances above all else are also at greater risk of developing symptoms. Lower accumulated dosage exposure to those thin-ness ideals in media and a lack of comprehensive knowledge on the entire subject may predispose women to pursuing unhealthy actions as a means to an end. Even in these specific cases however, adap-tive thoughts and behaviours may still be projected depending on the individual.

ReferencesBecker, A. E., Burwell, R. A., Herzog, D. B., Hamburg, P., & Gilman, S. E. (2002). Eating behaviours and attitudes following prolonged exposure to television among ethnic Fijian adolescent girls [Electronic version]. The British Journal of Psychiatry, 180, 509-514. Retrieved November 25, 2010 from Highwire Press database.Bissell, K. L., & Zhou, P. (2004). Must-see TV or ESPN: Enter tainment and sports media exposure and body image distortion in college women [Electronic version]. Jour nal of Communication, 54, 5-21. Retrieved October 8, 2010 from Wiley Online Library 2010 database.Fredrickson, B. L., & Roberts, T. (1997). Objectification theory: Toward understanding women’s lived experiences and mental health risks [Electronic version]. Psychology of Women Quarterly, 21, 173-206. Retrieved November 25, 2010 from Wiley Online Library 2010 database.Harper, B., & Tiggemann, M. (2008). The effect of thin ideal media images on women’s self-objectification, mood, and body image [Electronic version]. Sex Roles, 58,649 -657. Retrieved October 11, 2010 from SpringerLink database. Holmstrom, A. J. (2004). The effects of media on body image: A meta-analysis [Electronic version]. Journal of Broadcast & Electronic Media, 48, 196-217. Retrieved October 11, 2010 from Hein Online Law Journal Library database. Mills, J. S., Polivy, J. P., Herman, C. P., & Tiggemann, M. (2002). Effects of exposure to thin media images: Evidence of self-enhancement among restrained eaters [Electronic version]. Personality and Social Psychology Bulletin, 28, 1687-1699. Retrieved November 25, 2010 from Sage Premier database.Monro, F., & Huon, G. (2005). Media-portrayed idealized im ages, body shame, and appearance anxiety [Electronic version]. International Journal of Eating Disorders, 38, 85-90. Retrieved October 8, 2010 from Wiley On line Library 2010 database.


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Mumford, D. B., & Choudry, I. F. (2002). Body dissatisfaction and eating attitudes in slimming and fitness gyms in London and Lahore: A cross-cultural study [Elec tronic version]. European Eating Disorders Review, 8, 217-224. Retrieved November 25, 2010 from Academic Search Complete database.Noll, S. M., & Fredrickson, B. L. (1998). A meditational model linking self-objectification, body shame, and disordered eating [Electronic version]. Psychology of Women Quarterly, 22, 623-636. Retrieved November 25, 2010 from Sage Premier database. Owen, P. R., & Laurel-Seller, E. (2000). Weight and shape ideals: Thin is dangerously in [Electronic version]. Journal of Applied Social Psychology, 30, 979-990. Retrieved October 8, 2010 from Wiley Online Library 2010 data base. Spettigue, W., & Henderson, K. A. (2004). Eating disorders and the role of the media [Electronic version]. The Canadian Child and Adolescent Psychiatry Review, 13, 16-19. Retrieved October 11, 2010 from PubMed Cen tral database.Stice, E., Schupak-Neuberg, E., Shaw, H. E., & Stein, R. I. (1994). Relation of media exposure to eating disorder symp tomatology: An examination of mediating mechanisms [Electronic version]. Journal of Abnormal Psychology,103, 836-840. Retrieved October 11, 2010 from PsycARTICLES database. Tiggemann, A., & Pickering, A. S. (1996). Role of television in adolescent women’s body dissatisfaction and drive for thinness [Electronic version]. International Journal of Eating Disorders, 20, 199-203. Retrieved October 8, 2010 from Wiley Online Library 2010 database. Yamamiya, Y., Cash, T. F., Melnyk, S. E., Posavac, H. D., & Posavac, S. S. (2005). Women’s exposure tothin-and- beautiful media images: Body image effects on media-ideal internalization and impact-reduction interventions [Electronic version]. Body Image, 2, 74-80. Retrieved October 15, 2010 from ScienceDirect Freedom Collection database.


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50

Stress and the Common Cold: A Review Paper

Rauvynne N. Sangara

AbstractThe relationship between stress and the common cold has been heavily researched, primarily using the rhinovirus and the influenza A virus as the main virus replication models. The recent literature has consistently found that psychological stress leads to an increased chance of infection by the cold virus and an increase in common cold symptoms. Stress’s physiological affects on the body resulting in increased susceptibility to the common cold are currently unknown, but investigation has shown a link to hormones involved in immune system regulation.

IntroductionThe National Post estimates the social costs of the common cold in Canada at $400 million per year (Torkos, 2010). The detrimental cost of the common cold warrants the plethora of literature on its relation to stress. Psychological stress is widely experienced and often correlated with decreased health, but authors have yet to illustrate the mechanism by which it works. The common cold is not an exception to this struggle.

Due to their high incidence, Upper Respiratory Infections (URIs) have served as the primary model in studies seeking to link stress with infectious disease including the common cold (Cohen, Frank,

Doyle, Skoner, Rabin, & Gwaltney, 1998). Colds are caused and transmitted through viruses with the Rhinovirus family and the Influenza A virus being the most frequently used etiologic agents. Members of the Rhinovirus family are commonly used because they are not likely to cause illness that surpasses the severity of the common cold (Couch, 1984). Couch (1984) estimates that one half of respiratory illnesses are not caused by members of the Rhinovirus family. Only about one-third of those infected show common cold symptoms, so it is important to establish a boundary between infection and the development of a cold (Stone et al., 1992).

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The impressive prevalence of the common cold is both medically and economically concerning, making this an intriguing area of study for health psychologists. Researchers are interested in knowing how psychological states contribute to whether or not a person will develop symptoms after infection with the cold virus. Over the past thirty years there have been various groups focused on determining what types of stressors increase one’s susceptibility to the common cold and how these stressors work to decrease health. It has been illustrated by Broadbent (1984), Cohen (1991), Stone (1992), Divale (1995), and Takkouche (2000) that stress does in fact increase one’s susceptibility to URI, the common cold in particular. Unfortunately the mechanism underlying this relationship remains unclear; this paper aims to give a concise summary of the existing literature in hopes of clarifying inconsistencies between studies. In addition, this paper will review the current empirical data and critique the findings.

Overview Of Existing LiteraturePsychological Stress Increases Susceptibility to the Common ColdMost of the literature in this field explores the relationship between stress and susceptibility to the common cold by exposing participants to members of the Rhinovirus family. Sheldon Cohen (1991) and Arthur Stone (1992) are leading researchers in this field who use similar research methods. The majority of current studies find a relationship between psychological stress and greater susceptibility to the common cold although they all contain and control for different variables (Cohen, Tyrell, & Smith, 1991; Cohen, Tyrrell & Smith, 1993; Cohen et al., 1998; Cohen, 2005; Divale, 1995; Stone et al., 1992; Takkouche, Regueira & Gestal-Otero, 2000).

Cohen et al.’s (1991) research uses a stress index including three measures: number of major stress-ful life events as judged by the subject, the degree to which the subject thought the event exceeded their ability to cope, and an index of current negative af-fect. This particular study found that the rate of clini-

cal colds is greater with increases in the stress-index score (Cohen et al., 1991). Another study by Cohen tested the three components of the stress scale sepa-rately but found that highly stressed persons have higher rates of colds, irrespective of subjective stress scale ratings (Cohen, et al., 1993).

Figure 1 Adapted from “Psychological Stress and Susceptibility to the Common Cold” by S. Cohen, D. A. Tyrrell, and A. P. Smith, 1991, New England Journal of Medicine, 325, p. 609.

Stone’s (1992) study followed the same methods as previous studies but also included measures of mood and life events. Participants were separated from each other to avoid transference of the virus. Stone’s (1992) team used the Positive and Negative Affect Scale (PANAS) and the Perceived Stress Scale (PSS) to assess the well-being of participants. Consistent with the literature, those subjects reporting more negative life events developed more colds.

Takkouche et al. (2000) also investigated the relationship between stress and the common cold. Given that the cause of one-third to one-fourth of common colds is unknown, Takkouche’s (2000) studies focus on naturally occurring common colds rather then exposing participants to a virus. To further justify their method they argue that there is no information available revealing the dose of the virus necessary to produce a common cold, which could serve as a potential confound for Cohen’s earlier studies (Takkouche, et al., 2000). Further, Takkouche’s (2000) study focuses on the relationship


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between stress and the symptoms of the common cold rather than infection. In this study, four different dimensions of stress were investigated: stressful events, negative affect, positive affect, and perceived stress. Consistent with Cohen et al’s (1991; 1993; 1998) studies they found that high levels of psychological stress are associated with common colds (Takkouche et al., 2000).

Takkouche et al. (2000) also investigated the relationship between stress and the common cold. Given that the cause of one-third to one-fourth of common colds is unknown, Takkouche’s (2000) studies focus on naturally occurring common colds rather then exposing participants to a virus. To further justify their method they argue that there is no information available revealing the dose of the virus necessary to produce a common cold, which could serve as a potential confound for Cohen’s earlier studies (Takkouche, et al., 2000). Further, Takkouche’s (2000) study focuses on the relationship between stress and the symptoms of the common cold rather than infection. In this study, four different dimensions of stress were investigated: stressful events, negative affect, positive affect, and perceived stress. Consistent with Cohen et al’s (1991; 1993; 1998) studies they found that high levels of psychological stress are associated with common colds (Takkouche et al., 2000).

The Type of Psychological Stressor Matters

Figure 2 Adapted from “Types of Stressors That Increase Susceptibility to the Common Cold in Healthy Adults” by S. Cohen et al., 1998, Health Psychology, 17, p. 219.

More recent studies in this field investigated if the type of psychological stressor matters in terms of vulnerability to the common cold. Cohen and colleagues (1998) set out to establish the link between


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Table 1 Adapted from “Development of Common Cold Symptoms Following Experimental Rhinovirus Infection Is Related to Prior Stressful Life Events” by A. A. Stone et al., 1992, Behavioral Medicine, 18, p. 117.

type of stressor and susceptibility to URIs. Firstly, stressors were broken down into chronic or acute as assessed by a semi-structured interview, the Bedford College Life Events and Difficulties Schedule (LEDS).

As shown in Figure 2, those with chronic stressors were at higher risk for colds whereas those with acute stressors were not. The type of chronic stressor was assessed as: none, interpersonal, work, or other.

As shown in Figure 3, having either a work or interpersonal stressor increased the risk of acquiring a cold. Takkouche’s (2000) study on susceptibility to the naturally occurring cold also found that the type of stressor matters, and the results agree with Cohen et al.’s (1991; 1993; 1998) studies.

Personality and Lifestyle Variables Were Controlled ForA concern of Cohen’s (1993; 1998) was that the stress scale could represent state-related behaviour at the time of filling out the questionnaire rather than actual psychological stress. Thus, the degree of stress could reflect stable personality styles rather than responses to environmental factors. To account

for this, two personality factors related to stress were included in the studies—self esteem and personal control. A scale of introversion vs. extroversion was included due to evidence that suggests that introverts are at higher risk for infection (Broadbent, Phillpotts & Wallace, 1984; Totman, Kiff, Reed & Craig, 1980). Cohen’s 1998 study included a measure of five characteristics that serve as overarching traits to describe personality known as the Big Five. The five traits include openness to experience, conscientiousness, extraversion, agreeableness, and neuroticism. None of the individual personality variables accounted for were found to be significantly related to stress (Cohen et al., 1991; Cohen et al., 1998); therefore stable personality traits were not a factor in the relationship between stress and the common cold.

Cross-Cultural Implications Divale (1995) replicates the form of previous studies but adds factors of emotional state, rural vs. urban environmental, gender, and cultural background. Consistent with previous research, higher levels of stress corresponded with higher levels of cold illness. Furthermore, emotional dissatisfaction at school had


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Figure 3 Adapted from “Types of Stressors That Increase Susceptibility to the Common Cold in Healthy Adults” by S. Cohen et al., 1998, Health Psychology, 17, p. 219.

a greater negative effect on the immune system than did emotional dissatisfaction at home. The highest correlation was found between depression, stress, and cold symptoms (Divale, 1995). Rural inhabitants, females, Europeans and Hispanic participants reported more cold symptoms in general (Divale, 1995).

Why Does Stress Increase Susceptibility to the Common Cold?Stone et al. (1992) suggest that there are at least three points where psychological factors could affect symptomatology during infection: the reporting of symptoms, the response of end organs to inflammatory mediators, and the production of inflammatory factors. Cohen and colleagues (1991; 1993; 1998) assessed hormonal changes in participants to detect the mechanism by which stress works to weaken the immune system. Endocrine system function was measured via urinary levels of epinephrine, norepinephrine and cortisol. Immune pathways were measured through white blood cell and natural killer cell counts. Whereas an increase of epinephrine and norepinephrine predicted greater susceptibility, these effects were independent of the association between psychological stress and susceptibility; therefore they are most likely not contributors to the pathways linking psychological factors and disease susceptibility (Cohen, 2005).

Cohen and colleagues also entertained the possibility that stress interferes with the body’s ability to turn off proinflammatory cytokine production (Cohen, Doyle & Skoner, 1999). Cytokines are produced in response to URIs and are thought to account for common cold symptoms. After infection with the Influenza A virus, the proinflammatory cytokine interleukin-6 (IL-6) level was used to measure the response. Greater psychological stress was associated with higher symptom scores, greater mucus weights, and higher IL-6 concentrations. Correlational analyses were consistent with IL-6 acting as a mediator for the relationship between stress and symptoms (Cohen et al., 1999).

Participants who experienced more stress

experienced lower levels of cortisol (Cohen, 2005). Cortisol is a hormone released in response to stress; however, a feedback cycle often turns off cortisol in response to immense stress (Cohen, 2005). In response to cortisol, cells were found to produce less IL-6 (Cohen, 2005). This suggests that prolonged stress reduces cortisol, which then cannot turn off proinflammatory cytokines resulting in an increase of common cold symptoms. Suffice it to say, stress does not necessarily reduce the effectiveness of the immune system; it leads to dysregulation of other hormones, which in turn interferes with the body’s ability to respond to infection by a virus.

Summary and CritiqueStress is linked to decreased health on a number of different platforms. Through careful review of the literature it is clear that stress leads to increased episodes and symptoms of the common cold. Evidence from several studies has shown that increases in many different types of psychological stress lead to higher rates of infection by the rhinovirus and the influenza A virus, although the mechanism through which this interaction works is still unclear.

A better understanding of the pathways involved in the relationship between stress and the common cold is necessary to further our understanding of how a psychological phenomenon can map onto a physiological mechanism. Cohen et al.’s (1991; 1993; 1998; 2005) studies are extremely well controlled and potential confounding variables including personal behaviours and personality traits are well addressed. Although, with alternate variables controlled for, stress seems to affect the immune system, the underlying process causing this is unclear. Cohen and colleagues’ (1999) research using pro-inflammatory cytokine IL-6 concludes that increased stress does not reduce the immune system’s function per se, but interferes with the regulation of hormones, namely cortisol.

The original hypothesis was that stress reduced the immune system’s function, but literature to support this hypothesis is inconsistent. One reason for the


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dysregulation of hormones hypothesis is that it is hard to generalize these findings. Further, implying that stress interrupts the regulation of cortisol in the immune system is too unclear to be transferred to other chronic diseases. While Cohen et al. offered a mechanism that contributes to the knowledge of the relationship between stress and the common cold, a better understanding of the precise mechanism by which stress turns off cortisol regulation is necessary to be able to generalize these findings onto the wider field of stress and chronic illness.

Making it even more difficult to generalize these findings is the lack of a sound definition for stress. The lack of agreement on a universal definition of stress and an adequate scale to measure stress makes it hard to compare studies by different camps. In addition, the subjective nature of stress makes it hard to keep the studies controlled. Although Cohen et al. (1991; 1993) controlled for state-dependent behaviour, other authors did not. Stone (1992) also used nurses’ objective determination of cold symptoms to account for the subjective nature of symptoms, while other authors did not. Inconsistencies of this nature make it hard to compare data generated by different studies.

Using a virus to infect subjects is an adequate way to keep studies controlled; however as Takkouche (2000) and his team illustrated, having the symptoms of a cold and being infected are not the same, and not all common colds are caused by the viruses Cohen and others used. If we are looking to provide information for a better quality of life for people experiencing colds, we should be using data on naturally occurring colds because it is more valid. Although Takkouche’s (2000) study provided similar evidence to Cohen’s (1991; 1993; 1998), all other advancements that Cohen made were based on studies using virus models. In addition, the colds that are not caused by the Rhinovirus or the Influenza A virus might work by way of completely different mechanisms that have not yet been researched. While understanding more about how stress relates to the common cold and other diseases is important, one can be confident that a low stress lifestyle will ensure a greater chance for a healthy life.

ReferencesBroadbent, E., Broadbent, MHP., Phillpotts, RJ., & Wallace, J. (1984). Some further Studies on the prediction of experimental colds in volunteers by psychological factors. Journal of Psychosomatic Research, 28(6), 511- 523.Cohen, S. (2005). The Pittsburgh common cold studies: psychosocial predictors of susceptibility to respiratory infectious illness. International Journal of Behavioural Medicine, 12(3), 123-131. Cohen, S., Doyle, WJ., & Skoner, DP. (1999). Psychological stress, cytokine production, and severity of upper respiratory illness. Psychosomatic Medicine, 61, 175- 180.Cohen, S., Frank, E., Doyle, WJ., Skoner, DP., Rabin, BS., & Gwaltney, JM. (1998). Types of stressors that increase susceptibility to the common cold in healthy adults. Health Psychology, 17(3), 214-223.Cohen, S., Tyrrell, DAJ., & Smith, AP. (1993). Negative life events, perceived stress, negative affect, and susceptibility to the common cold. Journal of Personality and Social Psychology, 64(1), 131-140.Cohen, S., Tyrrell, DAJ., & Smith, AP. (1991). Psychological stress and the common cold. The New England Journal of Medicine, 325(9), 606-612.Couch, RB. (1984). The Common cold: control?. The Journal of Infectious Diseases, 150(2), 167-173.Divale, W. (1995). Cold symptoms and emotional dissatisfaction among rural/urban and culturally diverse high school students. Cross-Cultural Research, 29(1), 27-42.Stone, AA., Bovbjerg, DH., Neale, JM., Napoli, A., & Valdimarsdottir, H., Cox, D., Hayden, FG., Gwaltney, JM. (1992). Development of common cold symptoms following experimental rhinovirus infection is related to prior stressful life events. Behavioral Medicine, 18, 115- 120.Takkouche, B., Regueira, C., & Gestal-Otero, JJ. (2001). A Cohort study of stress and the common cold. Epidemiology, 11(3), 345-349.Torkos, S. (2010, February 17). The cost of the (far too) common cold and flu. Retrieved from http://www.nationalpost. com/related/links/story.html?id=2573721Totman, R., Kiff, J., Reed, SE., & Craig, JW. (1980). Predicting experimental colds in colunteers from different measures of recent life stress. Journal of Psychosomatic Research, 24, 155-163.


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